the optimisation of transfer chutes in the bulk materials

2009

The optimisation of transfer chutes in the bulk materials

industry

MN van Aarde

A dissertation submitted to the Faculty of Engineering in fulfilment of the

requirement for the degree

Magister Ingeneriae

In

Mechanical Engineering

At the North-West University Potchefstroom Campus

Promoter Dr M Kleingeld

Pretoria

ABSTRACT

ABSTRACT

Bulk materials handling is a rapidly growing global industry Immense challenges

exist to improve the efficiency and cost effectiveness of transporting and handling

bulk materials continuously The nature and scale of bulk materials handling

varies from country to country This study specifically focuses on the handling of

bulk materials in the mining sector

Within this industry transfer chutes are a key component used for transferring

bulk material from one conveyor to another Among other uses it can also be

used under hoppers or silos to transfer material to conveyors trains trucks or

ships In a continuous effort to improve the efficiency of processes the industry is

bombarded with transfer chute problems that include

bull blocked chutes

bull high wear of liner materials

bull spillage due to skew loading

bull conveyor belt wear at loading points

Thorough investigation of existing transfer points before modifying or replacing

them with another configuration gives better insight into the problems This aids

the designer to come up with the optimum solution for a speciAc transfer point In

this dissertation a study is done on the configuration of dynamic chutes or hood

and spoon chutes After completing a detailed investigation of existing problems

the study focuses on rectifying material transfer problems and designing for ease

of maintenance

Adding to the improved flow in the new design for the specific case study

discussed in this dissertation other design details are discussed which further

validates the new design This design improves the wear life of the liners inside

the chute and minimises down time by reducing maintenance shutdowns

The optimisation of transfer chutes in the bulk materials industry

MN van Aarde

ii

ABSTRACT

There are literally endless possibilities when it comes to chute configurations due

to the uniqueness of each plant material type and layout constraints It is

therefore beneficial to know what issues to address in the process of chute

design or optimisation

This study focuses on a specific case study with unique problems and solutions

It should however give further insight and a basic understanding of what a chute

designer must consider and the methods taken to optimise an existing material

transfer point The purpose of this document is therefore not to provide the

reader with a recipe for chute optimisation but rather with the knowledge to

comprehend the problems and solutions by discussing a specific industry case

study


MN van Aarde

iii

SAMEVATTING

SAM EVATTING

Materiaal handtering is n vinnig groeiende wereldwye industrie Hierdie industrie

word gekonfronteer deur groot uitdagings om die effektiwiteit van materiaal

handtering te verbeter en sodoende die koste daaraan verbonde te verminder

Die aard en skaal van materiaal handtering varieer van land tot land afhangende

van die vereistes wat gestel word deur daardie land se industriele sektor Hierdie

studie fokus spesifiek op materiaal handtering in die mynbou sektor waar

hoofsaaklik geprosesseerde erts handteer word

In hierdie industrie is oordrag geute n sleutel komponent en word dit hoofsaaklik

gebruik om erts te vervoer vanaf een vervoerband na n volgende Dit kan ook

onder andere gebruik word onder hoppers of sillos waar materiaal vervoer word

na vervoerbande treine vragmotors of skepe In die strewe om die effektiwiteit

van prosesse te verbeter word die industrie gekonfronteer met probleme wat

onder andere insluit

bull geblokkeerde oordrag geute

bull hoe slytasie op geut-voerring materiale

bull vermorsing van materiaal as gevolg van geute wat skeef aflaai op

vervoerbande

bull hoe slytasie van vervoerbande by uitlaai punte

Voordat bestaande probleem geute vervang word met n nuwe konfigurasie is dit

belangrik om n deeglike ondersoek te doen Hierdie ondersoek skep n beter

insig oor die probleme wat bestaan in die oordrag geute n Beter insig rondom

die probleme gee aan die ontwerper die vermoe om die optimale oplossing vir

die probleme te kry In hierdie skripsie is n studie gedoen oor die konfigurasie

van dinamiese geute of sogenaamde hood and spoon geute Bestaande

probleme word in ag geneem en die studie fokus op die verbetering van

materiaal vloei sowel as In ontwerp wat instandhouding vergemaklik ~~~~~~~~-


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iv

SAMEVATTING

As n toevoegsel tot die verbeterde vloei binne die nuwe ontwerp vir die

spesifieke geut waarna gekyk word in hierdie studie word daar ook ander

ontwerp toevoegings bespreek wat die waarde van die nuwe ontwerp verder

bevestig Hierdie ontwerp verbeter die leeftyd van die geut-voerring en tyd wat

afgestaan moet word aan instandhouding word geminimeer

Daar is letterlik eindelose moontlikhede wanneer dit kom by die konfigurasie van

oordrag geute as gevolg van die uniekheid van elke aanleg materiaal tipe en

uitleg beperkings Daarom is dit voordelig om te weet waaraan aandag gegee

moet word in die proses om geute te ontwerp of te optimiseer

Hierdie studie fokus op n spesifieke oordrag geut binne n spesifieke industrie

met unieke probleme en oplossings Dit behoort die geut ontwerper te bekwaam

met die basiese kennis en insig oor waarna om te kyk wanneer geute ontwerp of

geoptimiseer word Die doel van hierdie skripsie is dus nie om die leser te

voorsien van n resep om geute te optimiseer nie maar wei die kennis om die

probleme en oplossings te verstaan deur gebruik te maak van n studie uit die

industrie


MN van Aarde

v

ACKNOWLEDGEMENTS

ACKNOWLEDGEMENTS

I would like to thank Prof EH Mathews for the opportunity to do my Masters

degree

Special thanks to Dr M Kleingeld for his guidance and effort in assisting me in

my attempt to deliver a dissertation of this standard

Thank you to Prof Lesley Greyvenstein for the language editing

To my family thank you for all your support and encouragement throughout the

execution of this study

------________--__------------shyThe optimisation of transfer chutes in the bulk materials industry

MN van Aarde

vi

TABLE OF CONTENTS ---~-------------------~----

TABLE OF CONTENTS

Abstract ii

Samevatting iv

Acknowledgements vi

Table of contents vii

List of figures ix

List of tables xii

Nomenclature xiii

Chapter 1 Introduction to transfer chutes in the bulk materials handling industry1

11 Introduction to transfer chutes 2

12 Various applications and configurations of transfer chutes 5

13 Recurring chute problems and countermeasures from industry 11

14 Purpose of this research 18

15 Synopsis of this dissertation 19

Chapter 2 Basic considerations in chute design 21

21 Preface 22

22 Design objectives 22

23 Integrating a more appropriate chute layout with the plant constraints 27

24 Investigating the correct chute profile for reduced liner wear 30

25 Feed chute geometry for reduced belt wear 34

26 Conclusion37

Chapter 3 Tests for the identification of recurring problems on existing chutes39

31 Preface 40

32 Test methodology 40

33 Chute performance acceptance criteria 42

34 Discussion of problem areas 42

35 Summary of test results 54

36 Conclusion55


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vii

TABLE OF CONTENTS

Chapter 4 Dynamic chutes for the elimination of recurring problems 57

41 Preface 58

42 Consideration of the existing transfer point constraints 59

43 Design of the chute profile 61

44 Incorporating a dead box in the impact areas 67

45 Designing the chute for integration with system requirements 73

46 Conclusion75

Chapter 5 Testing and verification ofthe new solution 77

51 Preface 78

52 Selecting a test methodology 79

53 Determination of material properties 85

54 Verification of the selected test methodology for this application 88

55 Verification of new chute configuration and optimisation of the hood

location 92

56 Effect of the honeycomb structure in high impact zones 95

58 Conclusion 97

Chapter 6 Conclusions and Recommendations 99

61 Conclusions and recommendations 100

62 Recommendations for further study 103

References 1 05

Appendix A Material Tests And Liner Selection 111

Appendix B Chute Control Philosophy 116


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viii

LIST OF FIGURES

LIST OF FIGURES

Figure 1 Growth in global crude steel production from 1996 to 2006 [2] 2

Figure 2 Typical in-line transfer point [6] 4

Figure 3 90deg transfer point [7J 4

Fig ure 4 Material lump sizes through a crushing plant 6

Figure 5 Stacker Reclaimer in reclaiming mode 7

Figure 6 Typical dead box [11J9

Figure 7 Typical cascade chute [11] 9

Figure 8 Typical dynamic chute [12] 10

Figure 9 Radial door used in chutes under ore passes or silos [11] 1 0

Figure 10 Flopper gate diverting material to different receiving conveyors [11J 11

Figure 11 Ch ute liner degradation 12

Figure 12 Results of continuous belt wear at transfer points 13

Figure 1 Dust from a transfer point onto a stockpie13

Figure 14 Ceramic composite liners [18]15

Figure 15 Benetech Inteliflow J-Glide transfer chute [19] 16

Figure 16 Flow simulation of the Benetech Ineliflo chute [19] 17

Figure 17 Four step process for plant design and commissioning [1] 27

Figure 18 Vertical curve on incline conveyor 28

Figure 19 Protective roller on a transfer chute 29

Figure 20 Geometry of the impact plate and material trajectory [30J30

Figure 21 Model for the impact of a particle on a flat surface [29] 31

Figure 22 Ore flow path in the curved chute onto the incline conveyor [31] 35

Figure 23 Gentle deceleration of the product before impact on the receiving belt

[32] 35

Figure 24 Typical feed chute discharge model [33] 37

Figure 25 Layout of conveyors for chute test work 43

Figure 26 Configuration of the existing transfer chute44

Figure 27 Clear chute indicating camera angle 46


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ix

LIST OF FIGURES

Figure 28 Coarse material at 8 000 tlh 46

Figure 29 Fine material at 8 000 tlh 47

Figure 30 Blocked chute with coarse material at 8600 tIh 47

Figure 31 Damaged side skirt 49

Figure 32 View behind the chute of the receiving conveyor before loading 50

Figure 33 View behind the chute of the receiving conveyor during loading 50

Figure 34 Peak surges experienced during reclaiming operations 52

Figure 35 Stockyard head end layout 59

Figure 36 Dimensional constraints on the existing transfer configuration 60

Figure 37 Hood and spoon configuration for the 90deg transfer 63

Figure 38 Hood velocity profile 65

Figure 39 Spoon velocity profile 66

Figure 40 Chute cross section 67

Fig ure 43 Honeycomb wear box positioning 69

Figure 44 Wear box in the hood section 70

Figure 45 Spacing arrangement of honeycomb ribs inside the hood 71

Figure 46 Wear box in the spoon section 72

Figure 47 Liner detail of the spoon honeycomb wear box 73

Figure 41 Spoon in the operational position 74

Figure 42 Spoon in the non operational position 75

Figure 48 Flow analysis examples a) separation and screening b) hoppers

feeders [36J 80

Figure 49 Simulations results from Fluenttrade [4OJ 83

Figure 50 Simulation results from Bulk Flow Analysttrade [41J83

Figure 51 Determination of material properties for an accurate angle of repose88

Figure Actual material flow with coarse Sat 10 000 tIh 89

Figure 53 Material flow pattem through the existing chute 90

Figure 54 Cross sectional side view of material flow through the existing chute91

Figure 55 Material flow through hood at 10 000 tlh 92

Figure 56 Material flow through spoon at 10 000 tlh 93

Figure 57 Determination of the optimum hood location 94


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x

OF FIGURES

Figure 58 Material behaviour through hood 96

Figure 59 Material behaviour through spoon 96


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xi

LIST OF TABLES

LIST OF TABLES

Table 1 Design Input Reference Requirements [24J 24

Table 2 Iron are grades used for chute test work 45

Table 3 Results from test programme 54


M N van Aarde

xii

---------------------------------

CV

NOMENCLATURE

NOMENCLATURE

SCADA

CCTV

CEMA

DEM

kPa

mm

MSHA

ms

mt

MW

NIOSH

OSHA

RampD

tlh

3D

Supervisory Control And Data Acquisition

Closed Circuit Television

Conveyor Equipment Manufacturers Association

Conveyor

Discrete Element Method

Kilopascal

Millimetres

Mine Safety and Health Administration

Metres per second

Metric Tons

Megawatt

National Institute for Occupational Safety and Health

Occupational Safety and Health Administration

Radius of curvature

Research and Development

Tons per hour

Three Dimensional


MN van Aarde

xiii

CHAPTER 1

CHAPTER 1 INTRODUCTION TO TRANSFER CHUTES IN THE BULK

MATERIALS HANDLING INDUSTRY


MN van Aarde

1

CHAPTER 1

11 INTRODUCTION TO TRANSFER CHUTES

111 Bulk material handling industry

In order to comprehend the utilisation of transfer chutes fully it is imperative to

first understand the industry in which it is used Transfer chutes are most

commonly used in the bulk materials handling industry Bulk materials handling

operations perform a key function in a great number and variety of industries

throughout the world as stated in 1978 by Arnold McLean and Roberts [1 J

The nature of materials handling and scale of industrial operation varies from

industry to industry and country to country These variations are based on the

industrial and economic capacity and requirements of the specific industry or

country Regardless of the variations in industry the relative costs of storing

handling and transporting bulk materials are in the majority of cases very

significant

o

Figure 1 Growth in global crude steel production from 1996 to 2006 [2J


MN van Aarde

2

CHAPTER 1

The chart from BHP Billiton shown in Figure 1 provides a clear indication of the

actual drivers of global materials demand Figure 1 indicates the percentage

growth in crude steel production from all the major role players between 1996

and 2006 China accounted for 65 of the 494 million tonnes of global steel

production growth between 1996 and 2006 Europe grew by 6 while the other

countries grew by 20 [2]

These figures emphasise that bulk materials handling performs a key function in

the global industry and economy [1] Because of market requirements new

products continuously evolve This is also true for the field of bulk conveying

technologies [3] It can be assumed that the evolution of new technology is due

to the requirement for more efficient and cost effective operation

The case study which will be discussed from Chapter 3 onwards is an iron ore

export facility This facility exports approximately 50 million tonnes per annum

With each hour of down time the financial losses equate to approximately

R750 000 This highlights the fact that handling systems should be designed and

operated with a view to achieving maximum efficiency and reliability

112 Function of transfer chutes

BS2890 (Specification for Troughed Belt Conveyors) gives the definition for

transfer chutes as follows A straight curved or spiral open topped or enclosed

smooth trough by which materials are directed and lowered by gravity [4] For

any belt conveyor system to operate successfully the system requires that [5]

bull the conveyor belt be loaded properly

bull the material transported by the conveyor is discharged properly

The transfer of bulk material can either be from a belt bin hopper feeder or

stockpile and occurs at a transfer point In most cases this transfer point requires

optimisation of transfer chutes in the bulk materials industry

MN van Aarde

3

CHAPTER 1 - ----~--~--------------~--------

a transfer chute [5] In industry the most common use of transfer chutes is for

transferring bulk material from one conveyor belt to another This transfer of

material can be done in any direction as simplistically explained in Figure 2 and

Figure 3

Figure 2 Typical in-line transfer point [6J

Figure 2 shows a basic in-line transfer of material from the end of one conveyor

belt onto the start of another conveyor belt Figure 3 illustrates a more intricate

design where the direction of material transport is changed by an angle of 90 0 bull

This design or any other design entailing a directional change in flow normally

requires more detailed engineering [7


MN van Aarde

4

CHAPTER 1

Regardless of the direction or type of transfer there are some design

requirements that always need special attention Some of these requirements

are reduced wear on chute liners correct discharge velocity minimum material

degradation and minimum belt abrasion The correct design will also eliminate

blockages shape the load correctly and minimise the creation of dust [7]

12 VARIOUS APPLICATIONS AND CONFIGURATIONS OF TRANSFER CHUTES

The application of transfer chutes is central to any operation in the bulk handling

industry Whether it is mining operations storing stacking importing or

exporting of bulk material the transfer of material is always required On the

mining side the challenges involved with materials handling are probably some of

the most extreme

This is due to the great variation in lump sizes that must be catered for At

Sishen iron ore mine seven iron ore products are produced conforming to

different chemical and physical specifications The current mining process at

Sishen entails [8]

bull Removal of topsoil and stockpiling

bull Drilling and blasting of ore

bull Loading of iron ore and transporting to the crushers

bull Crushing and screening into size fractions

bull Beneficiation of all size fractions

bull Stockpiling onto various product beds

The processes with the most intricate and complex chute arrangements are

probably crushing and screening as well as stacking and reclaiming of material


11 N van Aarde

5

CHAPTER 1

121 Crushing

An excavator or wheeled loader transfers the rock to be crushed into the feed

hopper of the primary crusher The primary crusher breaks the large rock

boulders or run of mine material into smaller grain sizes Some of the bigger

crushers in the industry can crack boulders that are about one cubic meter in

size All the crushed material passes over a screen to separate the different

lump sizes The material that falls through the screen is transferred via a series

of transfer chutes and conveyor belts to the stockpile area [9]

Where the material does not pass through the screen another system of transfer

chutes and conveyor belts transfers this material to a secondary crusher The

material is fed into this crusher via a transfer chute from the discharge of a

conveyor belt All the processed material is then transferred to the stockpile area

via a separate series of transfer chutes and conveyor systems [9] Throughout

this whole process the material lump size changes and with it the transfer chute

requirements

Figure 4 Material lump sizes through a crushing plant


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6

CHAPTER 1

Figure 4 shows some spillage from a conveyor between a primary and secondary

crusher The shovel in the picture provides a good reference as to the variation

in material lump size on the walkway

122 Stacking and Recaiming

Normally the stockyard area has an elongated yard conveyor for moving bulk

material in the longitudinal direction of the stockyard Straddling the yard

conveyor transversely is the rail mounted undercarriage of the stacker reclaimer

Three main chutes transfer material through the machine [10] Figure 5 shows

this machine in action while reclaiming material from a stockpile

Figure 5 Stacker Reclaimer in reclaiming mode

The first chute will transfer material to the incline conveyor of the machine when

the material has to be stacked on the stockpile In the case where the material

must bypass the machine this chute will transfer material from the tripper back

onto the yard conveyor [10]


MN van Aarde

7

CHAPTER 1

The second chute transfers material from the incline conveyor onto the boom

conveyor This is normally a difficult process because the boom conveyor is

never in the same direction as the incline conveyor From the end of the boom

conveyor the material is Simply discharged onto the stockpile [10]

When reclaiming stockpile material the bucket whee at the head end of the

boom conveyor scoops up material and deposits it back onto the boom conveyor

From here it is discharged into the centre chute of the machine This chute then

discharges the material onto the yard conveyor for further processing In some

cases the bottom section of this centre chute must be moved out of the way to

allow free passage of material discharged from the tripper chute onto the yard

conveyor [10]

123 Chute configurations

Various chute configurations are used in the bulk materials handling industry

These configurations depend on the specific requirements of the system layout

or material properties There are basically two main configurations consisting of

dead box chutes and dynamic chutes Both of these configurations have their

specific applications in industry The major difference is that dead box chutes

use the material being transferred as a chute liner whereas dynamic chutes are

lined with a high wear resistant material A combination of both can also be

used

If the material being transferred is relatively dry such as goid ore dead boxes

prove to be more beneficial One of the applications of a ded box is to absorb

the direct impact of material discharged from a conveyor into a head chute as

can be seen in Figure 6 Other applications are in long or high transfer points In

these transfers the momentum of falling material must be reduced before

reaching the receiving conveyor belt in order to reduce wear of the belt [11]


MN van Aarde

8

CHAPTER 1

Figure 6 Typical dead box [11]

As shown in Figure 7 dead boxes are also used to accomplish changes in the

vertical flow direction by inserting angled panels This configuration where dead

boxes are used as deflection plates or impact wear plates is known as a cascade

chute In this case the deflection plate or the impact wear plate hardness is

equal to that of the feed material [11]

Figure 7 Typical cascade chute [11]

The hood and spoon chute or dynamic chute is configured so that the hood

catches and changes the material trajectory path to exit with a vertical velocity

When the material impacts the spoon it slides down the smooth spoon surface

The material flow direction is changed to the direction of the receiving conveyor

as shown in Figure 8 [12]


MN van Aarde

9

CHAPTER 1

Figure 8 Typical dynamic chute [12J

Ancillary equipment used with this configuration of chutes is radial doors and

flopper gates Radial doors are used successfully below ore passes or silos for

an onoff feed control as shown by Figure 9 One drawback of radial doors is the

possibility of jamming while closing In order to counteract this problem a

knocker arm between the cylinder door and the rod can be added This helps to

close the door with full force open with reduced force or hammered open [11]

Figure 9 Radial door used in chutes under ore passes or silos [11J


MN van Aarde

10

CHAPTER 1

The function of a f10pper gate is to divert the flow of material in a chute when one

conveyor is required to feed either of two discharge points as shown in Figure 10

For this same purpose a diverter car can also be used where a section of the

chute moves in and out of the path of material flow The critical area in the

design of a flop per gate is the hinge point In order for the gate to be self

cleaning the hinge point should be placed above the apex of the double chute

This also prevents rock traps that can jam the gate [11]

COVERED

Figure 10 Flopper gate diverling material to different receiving conveyors [11J

13 RECURRING CHUTE PROBLEMS AND COUNTERMEASURES FROM INDUSTRY

Transfer chutes are a fundamental link when conveying ore and therefore it is

important to get it right at the outset of design and fabrication Design and

fabrication issues can cause numerous problems when transferring material

Historically conveyor system design focused on the systems overall structural

integrity while ensuring that the equipment would fit within the facilitys

constraints [13] [14] [15]


MN van Aarde

11

CHAPTER 1

Little attention was given to design analysis or consideration for material flow

characteristics Normally the solution for controlling flow was to implement

simple rock boxes [15] This type of chute configuration is still commonly used in

industry but with more emphasis on the flow of material The most recurrent

problems on transfer chutes are [13] [14]

bull Spillage

bull Blocked chutes

bull High wear on the receiving belt due to major differences between the

material velocity and the belt velocity

bull Rapid chute wear

bull Degradation of the material being transferred

bull Excessive generation of dust and noise

bull Miss tracking of the receiving conveyor belt due to skew loading from the

transfer chute

Figure 11 Chute liner degradation

Figure 11 shows the excessive wear on ceramic tiles where the material

trajectory from the feeding belt impacts the chute These tiles are replaceable

and a maintenance schedule normally specifies the replacement intervals A

The optimisation of transfer chutes in the bulk materials industry 12

MN van Aarde

CHAPTER 1

problem arises when the frequency of these maintenance intervals is too high

due to excessive wear on the liners

Figure 12 Results of continuous belt wear at transfer points

The conveyor belt can account for up to 60 of the capital cost of a bulk

materials handling plant This means that the cost implications of constant

replacement of a conveyor belt due to wear can become significantly higher

than the original capital investment [16] Figure 12 shows the extreme damage

on a conveyor belt caused by abrasion and gouging

Figure 13 Dust from a transfer point onto a stockpile


MN van Aarde

13

CHAPTER 1 --~ ---------------------------shy

The presence of dust is an indisputable fact in many industries concerned with

the handling or processing of products such as coal mineral ores and many

others [17] As in the case of spillage it is easy to identify transfer systems that

cause dust clouds Environmental regulations are in place to prevent excessive I

dust emissions

Government organisations such as the Occupational Safety and Health

Administration (OSHA) the Mine Safety and Health Administration (MSHA) and

the National Institute for Occupational Safety and Health (NIOSH) closely monitor

dust levels at all coal handling facilities [13] Therefore it is imperative that the

chute design process caters for limiting dust emissions

Systems normally used in industry are enclosed skirting systems bag houses

and dust collectors This however is only treating the symptom rather than

eliminating the primary cause In order to minimise dust generation the use of

low impact angles and minimal chute contact is required (14] One of the most

successful methods of controlling dust is atomised water spray systems using a

combination of high pressure water and chemical substances

Over the years considerable research has gone into minimising wear on transfer

chutes There are currently a few different liner types to choose from depending

on the configuration and application of the chute These include ceramic tiles

chrome carbide overlay materials and typi~al hardened steel plates such as

VRN A combination of liner materials can also be used similar to the one

shown in Figure 14

The opUmisation of transfer chutes in the bulk materials industry

MN van Aarde

14

CHAPTER 1

Figure 14 Ceramic composite liners [18J

This ceramic composite liner is an example of the new technology available in

chute lining materials It is a high wear resistant surface made from cylindrical

alumina ceramic pellets bound within a resilient rubber base The purpose of this

material is to provide wear resistance through the use of ceramics while the

rubber dampens the impact forces [18]

Some innovative concepts for chute design have been implemented since the

materials handling industry started to incorporate new ideas Benetech Inc

installed a new generation hood and spoon type chute at Dominions 1200 MW

Kincaid coal powered generating station as shown in Figure 15 This chute

replaced the conventional dead box chute [19] Their innovation is to use a pipe

configuration combined with the hood and spoon concept


MN van Aarde

15

CHAPTER 1

Figure 15 Benetech Inteliflow J-Gide transfer chute [19J

This chute has sufficient chute wall slope and cross sectional area to prevent

material build-up and blocked chutes Reduced collision forces in the chute

minimize material degradation and the creation of excessive dust The material

velocity in the chute is controlled by the wall angles to obtain a discharge velocity

with the same horizontal component as the belt velocity [19] Figure 16 shows a

flow simulation of the Benetech concept The simulation shows that this concept

will result in lower impact forces and reduce belt abrasion


MN van Aarde

16

CHAPTER 1

Figure 16 Flow simulation ofthe Benetech Ineliflo chute [19J

CBP Engineering Corp also considers the concept of pipe type sections to be

the answer to most of the transfer chute problems They describe it as a curved

or half round chute The modern perception is to gently guide the material in the

required direction rather than use a square box design or deflector doors which

turns or deflects the flow [20]

The industry is striving towards developing new technology in transfer chute

design One solution is to incorporate soft loading transfer chutes to alter the

material flow direction with minimum impact on the side walls of chute and

receiving conveyor As experienced by many industries these types of chutes

can transfer material onto the receiving conveyor at almost the same velocity as

the conveyor By doing so many of the problems with material transfer can be

eliminated [13]

Most of these solutions as proposed by industry only address a few of the

numerous problems experienced with transfer chutes The dynamic hood and


MN van Aarde

17

CHAPTER 1

spoon chute appears to afford the best opportunity for solving most of the

problems There are still however many unanswered questions surrounding this

design

Figure 11 shows the installation of a hood type chute in the iron ore industry It is

clear from this image that liner wear in the higher impact areas is still an area of

concern Improvements can still be made to this design in order to further

enhance its performance

14 PURPOSE OF THIS RESEARCH

The bulk materials handling industry is constantly facing the challenge of

implementing transfer chutes that satisfy all the system requirements Problems

such as high wear spillage blockages and the control of material flow are just

some of the major challenges faced by the industry

The objective of this research is to identify problems experienced with transfer

chutes of an existing bulk handling system and to apply current design solutions

in eliminating these problems In doing so the research aims to introduce a new

method of minimising liner wear caused by high impact velocities

Dynamic chutes are discussed in particular where the entire design process

addresses the problems identified on chutes in brown field projects Approaching

chute design from a maintenance point of view with the focus on reducing liner I

degradation will provide a fresh approach to transfer chute design The

concepts disc~ssed in this dissertation (dynamic and dead box chutes) are

commonly used in industry However some research is done to determine

whether a combination of these concepts can solve some of the problems

experienced by industry


MN van Aarde

CHAPTER 1

At the hand of all the information provided in this dissertation its purpose is to

enable the chute designers to better understand the process of chute

optimisation and design This is achieved through the discussion of a case study

where the chutes are evaluated and re-designed to achieve the desired

performance

15 SYNOPSIS OF THIS DISSERTATION

Chapter 1 gives an introduction to the bulk materials industry and the role that

transfer chutes plays in this industry Some of the problems that the industries

have been experiencing with transfer chutes were identified and the diverse

solutions to these problems discussed These solutions were reviewed to

identify whether improvement would be possible

Chapter 2 provides a better understanding of the functionality and the

conceptualisation of transfer chutes as well as investigating the theory behind

material flow through transfer chutes This theory reviews the research and

design objectives used as a guideline when approaching a new chute

configuration The guidelines for evaluating and designing transfer chutes are

used to verify the performance of these chutes in the iron ore industry

Chapter 3 identifies some practical problems experienced on transfer chutes a~

an existing bulk transfer facility These problems are identified through a series

of tests where the actual flow inside the chutes is monitored via CCTV cameras

The results obtained from these tests are specific to this facility but can provide

insight into the cause of some problems generally experienced in the industry

These results can provide helpful information when modifying or re-designing

new transfer chutes

Chapter 4 uses the theory discussed in Chapter 2 to conceptualise a new

transfer chute configuration for the transfer points that were tested All the facility


MN van Aarde

CHAPTER 1

constraints are taken into account during the process in order to obtain an

optimum solution to the problems identified during the chute test work The old

chutes did not have major problems with liner wear due to large dead boxes

However this remains a serious consideration for the new dynamic chute design

due to its configuration where there is continuous sliding abrasion of the chute

surface A new concept for the reduction of liner degradation is introduced in this

chapter

Before manufacturing and installing this new concept it is important to verify that

it will perform according to conceptual design Chapter 5 is a discussion on the

use of the Discrete Element Method as a verification tool A simulation of the

new transfer chute concept is done to visualise the behaviour of the material as it

passes through the new transfer chute configuration

Chapter 6 discusses the benefits of the new transfer chute configuration A

conclusion is made as to what the financial implications will be with the

implementation of this new concept Recommendations are made for future

studies in the field of bulk materials handling These recommendations focus on

the optimisation of processes and the reduction of maintenance cost to the

facility


MN van Aarde

20

CHAPTER 2

CHAPTER 2 BASIC CONSIDERATIONS IN CHUTE DESIGN


MN van Aarde

21

CHAPTER 2

21 PREFACE

In an economic driven world the pressure for production is often the cause of the

loss of production This is a bold statement and is more factual than what the

industry would like to admit This is also valid in the bulk materials handling

industry Production targets seldom allow time for investigation into the root

cause of the problems The quick fix option is often adopted but is frequently the

cause of even more maintenance stoppages

Existing chutes on brown field projects often fail due to an initial disregard for the

design criteria changes in the system parameters or lack of maintenance

These transfer points are often repaired on site by adding or removing platework

and ignoring the secondary functions of a transfer chute Therefore it is

imperative to always consider the basic chute specifications when addressing a

material transfer problem [21]

22 DESIGN OBJECTIVES

In the quest to improve or design any transfer point some ground rules must be

set This can be seen as a check list when evaluating an existing chute or

designing a new chute Transfer chutes should aim to meet the following

requirements as far as possible [21] [22] [23]

bull Ensure that the required capacity can be obtained with no risk of blockage

bull Eliminate spillage

bull Minimise wear on all components and provide the optimal value life cycle

solution

bull Minimise degradation of material and generation of excessive dust

bull Accommodate and transfer primary and secondary scraper dribblings onto

the receiving conveyor


MN van Aarde

22

CHAPTER 2

bull Ensure that any differences between the flow of fine and coarse grades are

catered for

bull Transfer material onto the receiving conveyor so that at the feed point onto

the conveyor

bull the component of the material now (parallel to the receiving conveydr) is as

close as possible to the belt velocity (at least within 10) to minimise the

power required to accelerate the material and to minimise abrasive wear of

the belt

bull the vertical velocity component of the material flow is as low as possible so

as to minimise wear and damage to the belt as well as to minimise spillage

due to material bouncing off the belt

bull The flow is centralised on the belt and the lateral flow is minimised so as

not to affect belt tracking and avoid spillage

With the design of a new chute there are up to 46 different design inputs with 19

of these being absolutely critical to the success of the design Some of the most

critical preliminary design considerations are shown in Table 1 [24]


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23

CHAPTER 2

Table 1 Design Input Reference Requirements [24J

Aria Unit

Feed Conveyor

Belt Speed r ms

Belt Width mm

JibHead Pulley Dia mm

Pulley Width mm

Angle to Horizontal at the Head Pulley degrees

Belt Troughing Angle degrees

Sight Height Data

Feed Conveyor Top of Belt to Roof mm

Drop Height mm

Receiving Conveyor Top of Belt to Floor mm

Receiving Conveyor

Belt Speed ms

Belt Width mm

Belt Thickness mm

Angle of Intersection degrees

Angle to Horizontal degrees


Material Properties

Max Oversize Lump (on top) mm

Max Oversize Lump (on top) degrees

studies done by Jenike and Johanson Inc have identified six design principles

that can serve as a guideline in chute optimisation exercises These six

principles focus on the accelerated flow in the chute which they identified as the

most critical mode [25]

Within accelerated flow the six problem areas identified by Jenike and Johanson

Inc are [25]

The optimisation of transfer chufes in the bulk materials industry

MN van Aarde

24

CHAPTER 2

bull plugging of chutes at the impact points

bull insufficient cross sectional area

bull uncontrolled flow of material

bull excessive wear on chute surfaces

bull excessive generation of dust

bull attrition or breakdown of particles

221 Plugging of chutes

In order to prevent plugging inside the chute the sliding surface inside the chute

must be sufficiently smooth to allow the material to slide and to clean off the most

frictional bulk solid that it handles This philosophy is particularly important

where the material irnpacts on a sliding surface Where material is prone to stick

to a surface the sliding angle increases proportionally to the force with which it

impacts the sliding surface In order to minimise material velocities and excessive

wear the sliding surface angle should not be steeper than required [25]

222 Insufficient cross sectional area

The cross section of the stream of material inside the chute is a function of the

velocity of flow Therefore it is critical to be able to calculate the velocity of the

stream of material particles at any point in the chute From industry experience a

good rule of thumb is that the cross section of the chute should have at least two

thirds of its cross section open at the lowest material velocity [25] When the

materialis at its lowest velocity it takes up a larger cross section of chute than at

higher velocities Therefore this cross section is used as a reference

223 Uncontrolled flow of material

Due to free falling material with high velocities excessive wear on chutes and

conveyor belt surfaces are inevitable Therefore it is more advantageous to


MN van Aarde

25

CHAPTER 2

have the particles impact the hood as soon as possible with a small impact

angle after discharge from the conveyor With the material flowing against the

sloped chute walls instead of free falling the material velocity can be controlled

more carefully through the chute [25]

224 Excessive wear on chute surfaces

Free flowing abrasive materials do not normally present a large wear problem

The easiest solution to this problem is to introduce rock boxes to facilitate

material on material flow Chute surfaces that are subjected to fast flowing

sticky and abrasive materials are the most difficult to design

A solution to this problem is to keep the impact pressure on the chute surface as

low as possible This is done by designing the chute profile to follow the material

trajectory path as closely as possible By doing so the material is less prone to

stick to the chute surface and the material velocity will keep the chute surface

clean [25]

225 Excessive generation of dust

Material flowing inside a transfer chute causes turbulence in the air and

excessive dust is created In order to minimise the amount of dust the stream of

material must be kept in contact with the chute surface as far as possible The

material stream must be compact and all impact angles against the chute walls

must be minimised A compact stream of material means that the material

particles are flowing tightly together At the chute discharge point the material

velocity must be as close as possible to the velocity of the receiving belt [25]

The optimisation of transfer in the bulk materials industry

M N van Aarde

26

CHAPTER 2

226 Attrition or breakdown of particles

The break up of particles is more likely to occur when large impact forces are

experienced inside a chute than on smooth sliding surfaces Therefore in most

cases the attrition of material particles can be minimised by considering the

following guidelines when designing a transfer chute minimise the material

impact angles concentrate the stream of material keep the material stream in

contact with the chute surface and keep the material velocity constant as far as

possible [25]

23 INTEGRATING A MORE APPROPRIATE CHUTE LAYOUT WITH THE PLANT

CONSTRAINTS

According to Tunra Bulk Solids in Australia the process for design and

commissioning of a new plant basically consists of four steps The entire

process is based on understanding the properties of the material to be

handled [1]

RampD CENTRE CONSULTING CONTRACTOR ENGINEERING AND PLANT

COMPANY OPERATOR r-------------- I TESTING Of CONCEPTUAl I DETAILED DESIGN CONSTRUCTION amp

I BULKSOUDS - DESIGN COMMISSIONING- I shyI Flow Proper1ies Lining Material tuet Equipment

Selection Procurement _ I I

I I

I Flow Pat1erns SSlpment Quality Control I

I IFeeder Loads amp Process Performance

I Power I Optimisation Assessment I I

L J -

I IBin Loads I I I Wear Predictions I

FEEDBACK I I I IModel Studigt L _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ J

i ~ FEEDBACK r-shyFigure 17 Four step process for plant design and commissioning [1J


MN van Aarde

27

CHAPTER 2

Figure 17 illustrates this four step process These steps are a good guideline in

order to incorporate a more appropriate chute layout for the plant constraints

This is an iterative process where all the possible solutions to a problem are

measured against all the possible plant constraints This section focuses more

on the second column of Figure 17 and specifically on structures and equipment

During this stage of design the utilisation of 3D parametric modelling also creates

an intimate and very accurate communication between the designer and the

project engineer or client This effective communication tool will save time and

improve the engineering process [24]

A good example of obtaining an appropriate chute layout for the plant constraints

can be explained as follows On an existing plant a transfer point will have a

specific transfer height from the top of the feed conveyor to the top of the

receiving conveyor If the feed conveyor has an incline section to obtain the

required transfer height it will also have a curve in the vertical plane of that

incline section This curve has a certain minimum radius in order to keep the belt

on the idlers at high belt tensions [26]

Figure 18 Vertical curve on incline conveyor


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CHAPTER 2

If the transfer height at a transfer point is changed the path of the feeding

conveyor should always be taken into consideration With an increase in transfer

height the vertical curve radius will increase as well in order to prevent the

conveyor from lifting off the idlers in the curve This will require expensive

modifications to conveyor structures and therefore in most cases be a pointless

exercise Figure 18 shows clearly the large radius required to obtain a vertical

curve in a belt conveyor

Other considerations on brown field projects might be lift off of the receiving

conveyor at start up before or after the vertical curve This is caused by peaks

in belt tension at start up which may cause the belt to lift off the idlers and chafe

against the chute In some cases this can be solved by fitting a roller as shown

in Figure 19 to the underside of the chute to protect it from being damaged by

the belt or to protect the belt from being damaged by the chute The position of

this specific chute is just after a vertical curve where the belt tends to lift off at

start up

Figure 19 Protective roller on a transfer chute


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CHAPTER 2

24 INVESTIGATING THE CORRECT CHUTE PROFILE FOR REDUCED LINER WEAR

In order to reduce chute wear the curved-profile variable chute concept is

introduced [27] This concept was originally developed by Professor Roberts for

the grain industry in 1969 [28] After many years of research and investigation

CMR Engineers and Project managers (pty) Ltd came to the following

conclusion any improvement in coal degradation dust generation and chute

wear can only be achieved by avoiding high impact forces or reducing them as

much as possible [27]

At any impact point of material in a chute or conveyor kinetic energy is

dissipated This increases material degradation and wear on liners and conveyor

belt covers Therefore it is good practise to redirect the kinetic energy in a

useful manner This action will help to reduce liner and belt wear [32]

x

Vo

- ImpactPlate

Figure 20 Geometry of the impact plate and material trajectory [30J

The optimisation of transfer chutes n the bulk materials industry

MN van Aarde

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CHAPTER 2

The path followed by the material discharged over the end pulley of a belt

conveyor is known as its trajectory and is a function of the discharge velocity of

the material from the conveyor [29] Figure 20 shows the material trajectory as

weI as the radius and location of the impact plate In the case of dynamic chutes

this impact plate represents the back plate of the chute

The correct chute profile to reduce wear must cater for the proper location of the

chute covers and wearing plates This location depends upon the path of the

trajectory which must be predicted as accurately as possible

Figure 21 Mode for the impact of a particle on a flat surface [29]

Figure 21 illustrates a material particle impinging on a flat chute surface at an

angle of approach 91 and with approach velocity V1 This particle will then

rebound off the chute plate at an angel 92 and velocity V2 The wear on the

chute liners or the surface shown in Figure 21 will be a function of the vector

change in momentum of the particle One component will be normal to and the

other component parallel to the flat surface The parallel component is referred

to as the scouring component along the surface [29]

It is important to determine the radius of curvature of material within the

trajectory It is now a simple exercise to determine the chute hood radius

depending on plant constraints Firstly the material trajectory must be calculated


MN van Aarde

31

CHAPTER 2 ---~----------------

According to the mechanical handling engineers association in Perth Australia it

is beneficial to keep the impact angle as small as possible Impact angle less

than 20deg are recommended for most liner materials This will ensure an

acceptably small impulse force component normal to the surface The r~te at

which the material is gouging away the chute liner at the impact point will be

reduced [29]

The material trajectory is determined by equation l

(1)

Where the origin of the x and y axis is taken at the mean material height h and

the discharge point on the pulley as shown in Figure 20 The variables involved

in the calculation of the material trajectory are [30]

y =vertical position on the grid where the trajectory is determined

x = position parallel to the receiving belt line where the trajectory is determined

v = material speed

g =gravitational constant

a =inclination angle of the feeding conveyor

After the material leaves the belt a simplified assumption can be made that it

falls under gravity It is quite clear that in order to minimise the impact angle

the impact plate must follow the path of the material trajectory as far as possible

It will almost never be possible to obtain a contact point between the material and

the chute where there is a smooth contact with no impact angle

This radius of curvature of the material tr~jectory is determined as follows [30

The optimisation of transfer chutes in the bulk materials industry i 32

MN van Aarde

CHAPTER 2

[1 + ( gx )]15 R = vcos8

c (2)

vcos8

Where

g == gravitational constant

v == material speed

8 == Angle at discharge

In order to simplify the manufacturing process of a curved chute the radius must

be constant For a relatively smooth contact between the material and the chute

plate the radius of the curved chute at the point of contact is as close as

possible to the material discharge curvature radius [30] This is rarely possible

on brown field projects due to facility constraints In this case there will be higher

probability for rapid liner wear Each situation must be individually assessed to

determine the best solution

Cross sectional dimensions of the transfer chute must be sufficient to collect the

material and ensure continuous flow without causing blockages At the same

time the chute profile must not result in excessive material speed Material

speed inside the chute will be considered to be excessive when it can not be

controlled to exit the chute at approximately the same velocity to that of the

receiving conveyor Chutes may block for the following reasons [29]

bull Mechanical bridging due to large lumps locking into one another

bull Insufficient cross section causing cohesive material to choke or bridge

bull Inadequate chute inclination causing fines build-up

bull Corner effects or cohesion causing material to stick to the chute walls


MN van Aarde

33

CHAPTER 2

For the handling of large lumps of material field experience has shown that the

chute cross sectional area should be 25 times the major dimension of the largest

lumps To avoid possible bridging of the material in the chute the

recommendation is to make the inner chute volume as large as possible This

will be guided by the support steelwork around the transfer point [29]

Field experience has shown that it is advisable depending on the material being

transferred that the chute inclination angles be no less than 65deg to 700 Cornerbull

effects should also be avoided where material gets stuck in the inner corners of

chute plate work These angles should preferably be no less than 70 0 bull

25 FEED CHUTE GEOMETRY FOR REDUCED BELT WEAR

The design parameters to reduce both chute and belt wear are interrelated

Research done at the Phalaborwa copper mine is a good case study to prove the

concept of a curved chute profile This mine had specific problems with high belt

wear at transfer points At this facility an in-pit 60 x 89 gyratory crusher and

incline tunnel conveyor was commissioned to haul primary crushed ore A

conventional dead box chute transfers ore from the crusher to a 1800 mm wide

incline conveyor [31]

The maximum lump size handled by this section of the facility is 600 mm (60 kg)

An 18 mm thick top cover was specified for this conveyor with an X grade

rubber according to DIN (abrasion value lt 100 mm) This belt had an original

warranty of 10 years After 35 years the top cover started to show signs of

excessive wear and the tensile cords of the 18 mm thick cover were visible [31]

In April 1994 Phalaborwa commissioned the curved chute concept and a new

belt on the incline conveyor Six months after commissioning no gouging or

pitting damage was evident The material velocity through this curved chute onto

the incline conveyor is shown in Figure 22 [31]


MN van Aarde

34

CHAPTER 2

VELOCITY ( m I aec ) _ nm _ bull m _ 1211 _ UTI _ U16

_ IIU _ Im _ I rn _ 171-111 _ u n _ ~ l

_ 4 ~

_ 41 _ 4

141 CJ UtiI 1bull-bull 1t5

~ 1m bull UI2

Material Flow Velocity Gradient

Figure 22 Ore flow path in the curved chute onto the incline conveyor [31]

TENDENCY TO FORM STAGNANT LAYER LEADING

TO INSTABILITY IN DEPTH OF FLOW

C8middotFLOW IN CURVED CHUTES

Figure 23 Gentle deceleration of the product before impact on the receiving belt [32]


MN van Aarde

35

CHAPTER 2

Figure 23 illustrates the gentle deceleration of material that is achieved with the

curved chute concept This helps to reduce belt wear because it is relatively

easy to discharge the material at the same velocity as the receiving conveyor

The material speed v can be calculated at any point in the chute using equation

3 and equation 4 [33]

v 2~R [(2ue2 -l)sin(O) +3ue cos(O)] + Ke 2uB (3) 4ue +1

This equation is only applicable if the curved section of the chute has a constant

radius Rand I-Ie is assumed constant at an average value for the stream [33]

I-Ie = friction coefficient

8 = angle between the horizontal and the section of the spoon where the velocity

is determined and

(4)

The optimisation of transfer chutes in the bulk materjas industry

MN van Aarde

36

CHAPTER 2

Mass Flow Rate Omh

Figure 24 Typical feed chute discharge model [33J

The velocity Ve at the discharge of the chute can be determined from equation 3

and equation 4 The components Vey and Vex of the discharge velocity as

shown in Figure 24 can now be calculated This investigation should aid the

optimisation of the chute profile in order to [33]

bull match the horisontal component Vex of the material exit velocity as close

as possible to the belt speed

bull reduce the vertical component Vey of the material exit velocity in order to

minimize abrasive wear on the receiving conveyor

26 CONCLUSION

This section discussed the technical background necessary for the optimisation

of transfer chutes on an existing iron ore plant which will be discussed in

Chapter 4 The focus is specifically aimed at reducing impact wear on chute liner

materials and abrasive wear on receiving conveyor belts Important to note from

The optimisation oftransfer chutes in the bulk materials industry

MN van Aarde

37

CHAPTER 2

this section is the acceptable limits of dynamic chute optimisation or design

These limits aremiddot

bull a material impact angle of less than 20deg

bull a variance of less than 10 between the receiving belt velocity and the

material discharge velocity component parallel to the receiving conveyor

An important aspect of chute optimisation is to consider the facility constraints

These constraints are in some cases flexible but in most cases the chute

optimisation process must be designed within these constraints This means that

any new concept will have to be measured against what is possible within the

facility limits

It is important to note that only the most common transfer chute problems were

mentioned in this chapter Other possible problems were not addressed in this

chapter as it is normally related to detail design issues Solutions to these

problems are unique to each type of chute and will be addressed for the specific

case study in Chapter 4

The optimisafjon of transfer chutes in the bulk materials industry

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38

CHAPTER 3


MN van Aarde

CHAPTER 3 TESTS FOR THE IDENTIFICATION OF RECURRING

PROBLEMS ON EXISTING CHUTES

39

CHAPTER 3

31 PREFACE

Since the completion of a certain iron ore handling facility it has been

experiencing recurring material transfer problems at high capacities In order to

investigate the problem it was decided that performance testing of the chutes

should be carried out The purpose of these tests was to monitor chute

performance at transfer rates of up to the design capacity of 10 000 tlh for

various grades of iron ore handled by the facility Some of the methodologies

used in testing are only applicable to this specific facility

Due to variations and surges associated with the reclaim operations at the

facility performance testing focused on reclaim side chutes This means that all

the transfer points at the exit points of the stockyard conveyors were tested

Nineteen tests were conducted on various stockyard transfers Information such

as the specific facility or conveyor numbers cannot be disclosed due to the

confidentiality of information

To analyse SCADA data the stacker reclaimer scale is used to determine the

peak surges passing through the transfer under investigation The reason for

this is that the peaks in flow due to reclaiming operations flatten out when

passing through the transfer points This is due to chute throat limitations and

small variations in belt speeds If the down stream scales are used it would give

an inaccurate indication of the amount of ore that passed through the transfer

chute

32 TEST METHODOLOGY

A CCTV camera was installed in a strategic position inside the head chute of the

stockyard conveyors These cameras provided valuable information on the

physical behaviour of the material flow inside the transfer chutes Where

possible cameras were also placed on the receiving belt in front of and behind


MN van Aarde

40

CHAPTER 3

the chute This was done to monitor belt tracking and spillage A high frequency

radio link between the head chute and the control tower made it possible to

monitor the cameras at all times

SCADA data was used to determine and establish the condition of the material

transfer at the time of the test Data from various scales en route were obtained

as well as confirmation of blocked chute signals In analysing the SCADA data

the stacker reclaimer scale is used to determine the peak surges passing through

the transfer being tested

Data was recorded from a sampling plant at the facility This data provides the

actual characteristics of representative samples taken and analysed by the

sampling plant during the duration of the test The data gathered consist of

moisture content of the material sample as well as the size distribution of the ore

Where possible an inspector was placed at the transfer point being tested to

observe and record the performance The inspector had a two way radio for

communication with the test co-ordinator in the central control room He would

also be responsible for the monitoring of any spillage dust emissions etc that

may not be picked up by the cameras

Prior to commencing a test on a specific conveyor route the following checks

had to be performed on all the material conveying equipment

bull Clean out all transfer chutes and remove any material build-up from the

sidewalls

bull Check that feed skirts are properly in position on the belt

bull Check that the conveyor belt is tracking properly at no load

bull Check conveyor idlers are all in position and free to rotate

bull Check blocked chute detectors are operational and in the correct location


MN van Aarde

CHAPTER 3

bull Change the position of the blocked chute detector if required to improve its

fUnction

bull Test and confirm that the CCTV middotsystems are functioning correctly

bull Assign persons with 2 way radios and cameras to monitor and record the I

results at each transfer point on the route

33 CHUTE PERFORMANCE ACCEPTANCE CRITERIA

A material transfer chute performs to specification if it transfers a maximum of

10 000 tlh of a specific iron are grade without experiencing any of the following

problems

bull Material build up inside the chute or blocking the chute ie material is not

exiting the chute at the same rate as it is entering

bull Material spillage encountered from the top of the transfer chute

bull Material spillage encountered where material is loaded onto the receiving

conveyor

bull Belt tracking of the receiving conveyor is significantly displaced by the

loading of material from the transfer chute onto the conveyor

Tests were conducted over a period of one month and in such a short period

visible wear is difficult to quantify Due to the sensitivity of the information no

historical data in terms of chute or belt wear were made available by the facility

Therefore it is not part of the criteria for these specific tests Should a chute

however fail to perform according to the set criteria it validates the need for

modifications or new designs

34 DISCUSSION OF PROBLEM AREAS

The major concern during the test work is material flow at the transfer points

Secondary concerns are spillage tracking of the receiving belt and material


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42

CHAPTER 3

loading onto the receiving belt One of the external factors that playa significant

role in material flow rate is the method and process of reclaiming This section

will highlight all the problem areas observed during the test work

Figure 25 shows the layout of the stockyard area This layout will serve as a

reference when the specific test results at each transfer point are discussed The

legends for Figure 25 are as follows

c=gt Transfer points where performance tests have been done

~ Direction that the conveyors are moving in

CV4 CV3 CV2 CV1

Figure 25 Layout of conveyors for chute test work

All four stockyard conveyors have a moving head arrangement This means that

the chutes are split up into two sections A moving head discharges material

onto either conveyor (CV) 5 or CV 6 via a static transfer chute The moving

head positions are shown by A Band C in Figure 25


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43

CHAPTER 3

Position C is the purging or dump position This position is used when the

stacker reclaimer is in stacking mode and any material left on the stockyard

conveyor gets dumped The material does not end up on the stockpiles

preventing contamination

90 de-g TRANSFBt

OfAO BOX IN MOVING HEAD

Figure 26 Configuration of the existing transfer chute

Figure 26 shows the configuration of the existing transfer chutes These chutes

capture the trajectory from the head pulley in a dead box situated in the top part

of the chute The material then cascades down a series of smaller dead boxes

onto the receiving conveyor below

Various grades of iron ore were tested during the testing period These different

grades of iron ore are shown in Table 2 Three fine grades and four coarse

grades were used The coarse material is defined as particles with a diameter of


MN van Aarde

44

CHAPTER 3

between 12 mm and 34 mm and the fine material with diameters of between

4 mm and 12 mm

Table 2 Iron are grades used for chute test work

Material Predominant Lump Size

Fine K 5mm

Fine N 8mm

Fine A 8mm

Coarse K 25mm

Coarse D 34mm

Coarse S 12 mm

Coarse A 20mm

The CCTV cameras were placed inside the moving head pointing down into the

static chute overlooking the receiving conveyor Figure 27 shows the camera

angle used during testing This is a view of a clear chute before testing The

legends for clarification of all the video images are as follows

Front of the chute throat opening

Top of flowing material at the chute throat opening

Flow pattern of the material

Direction of the receiving belt


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CHAPTER 3

Figure 27 Clear chute indicating camera angle

341 Coarse Material vs Fine Material

Differences in transfer rates between coarse material and fine material are

evident from the data gathered during the test programme These results are

discussed later in this chapter The area between the yellow arrows and the red

line is the amount of freeboard available Freeboard is the open space available

between the top of the flowing stream of material and the chute plate work

Figure 28 and Figure 29 shows the flow of coarse ore and fine ore respectively in

the same chute at 8 000 tlh

Figure 28 Coarse material at 8 000 tlh


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46

CHAPTER 3

Figure 29 Fine material at 8 000 tlh

The amount of freeboard with fine material is much larger than with coarse

material It is therefore obvious that coarse material is more likely to block a

chute when peak surges occur This is due to particles that interlock in the small

discharge opening of the chute

Figure 30 Blocked chute with coarse material at 8 600 tIh

Figure 30 is a snap shot of a chute blocked with coarse ore due to the material

interlocking at the discharge opening The time from material free flowing to a

blocked chute signal was approximately 10 seconds This is determined by

comparing the CCTV camera time to the blocked signal time on the SCADA


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CHAPTER 3

The high clay content in finer material can also cause problems in the long run

When wet Anes are fed through the chutes a thin layer of Anes builds up and

sticks to the sides of the chute As this layer dries out it forms a new chute liner i

and the next layer builds up This process occurs gradually and will eventually

cause the chute to block

342 Cross Sectional Area

Video images of a blocked chute on the receiving belts were analysed to

determine whether the blockage was caused by material build up on the belt

underneath the chute This indicated that with the occurrence of a blocked chute

the material keeps flowing out of the chute at a constant rate without build up

From this the assumption can be made that in the case of a blocked chute the

material enters the chute at a higher rate than it is discharged at the bottom

Therefore the conclusion can be made that the chute cross sectional area at the

discharge is insufficient to handle the volume of ore at high throughput rates

Tests with a certain type of coarse material yielded a very low flow rate requiring

adjustment to the chute choke plate on the transfer between CV 3 and CV 5

The chute choke plate is basically a sliding door at the bottom of the chute to

adjust the discharge flow of material Tests with another type of coarse material

shown in the summary of test results indicates how the choke plate adjustment

can increase the throughput of material in the chute

Data of all the different types of ore at the facility are obtained at the sampling

building This data shows that the material size distribution for the two types of

coarse material used in the tests mentioned above are the same This indicates

that the test results with the second coarse material are an accurate reflection of

what will be experienced with the first type of coarse material Special care


MN van Aarde

48

CHAPTER 3

should be taken when adjusting the choke plate to make sure that skew loading

is not induced by the modification

343 Spillag3

During one of the first tests on the transfer between CV 2 and CV 6 spillage

was observed at one of the side skirts on the receiving belt A piece of the side

skirt had been damaged and pushed off the belt as shown by Figure 31 This

caused some of the material to be pushed off the belt when skew loading from

the chute caused the belt to miss track In this case spillage was not caused by

the skirt but by skew loading from the chute onto the receiving conveyor

Figure 31 Damaged side skirt

A greater concern is spillage on the moving head chute of CV 3 and CV 4

loading onto CV 6 It appears as if the head chute creeps during material

transfer onto CV 6 As the chute creeps the horizontal gap between the

moving head chute and the transfer chute reaches approximately 180 mm

Facility operations proposed a temporary solution by moving the head chute to

the dumping or purging position and back to CV 5 before stopping over CV 6

The reason for this creep could be attributed to slack in the moving head winch

cable


MN van Aarde

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CHAPTER 3

345 Belt Tracking and Material Loading

The only belt tracking and material loading problems observed occurred on the

transfer between CV 2 and CV 5 I CV 6 A diverter plate was installed at the

bottom of the chute in order to force material flow onto the centre of the receiving conveyor belt This plate now causes material to fall to the left of the receiving

belt causing the belt to track to the right

Figure 32 View behind the chute of the receiving conveyor before loading

Figure 32 shows the view from a CCTV camera placed over the receiving

conveyor behind the chute Note the amount of the idler roller that is visible

before loading

Figure 33 View behind the chute of the receiving conveyor during loading


MN van Aarde

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CHAPTER 3


conveyor behind the chute during loading Note the difference between the

amount of the idler roller that is visible between Figure 33 and Figure 32 This is

a clear indication of off centre belt tracking due to skew loading I

At the same transfer point it appears as if the configuration of the chute causes

the material to be dropped directly onto the receiving belt from the dead box in

the moving head This will cause high impact wear on the belt in the long run

High maintenance frequencies will be required on the impact rollers underneath

the chute and the roller bearings will have to be replaced frequently

346 Reclaiming Operations

Reclaim operations are done from the stacker reclaimer that scoops up the

material with a bucket wheel from the stockpile The machine starts at the top

bench of the stockpile and reclaims sideways until it is through the stockpile

This sideways movement is repeated while the machine moves down the

stockpile If the machine digs too deep into the stockpile small avalanches can

occur that over fill the buckets This causes peak surges in the flow on the

conveyor system

With an increase in the peak digging or reclaim rate as requested for test work it

seemed that the peak surges increased as well In normal reclaiming operations

(average reclaim rate of 6 000 tlh to 7000 tlh) the peaks in reclaim surges do not

usually exceed 1 000 tlh This is however dependent on the level of the

stockpile from where the machine is reclaiming

At a peak digging or reclaim rate of 8 000 tlh peak surges of up to 2 000 tlh were

observed as can be seen from Figure 34 All stacker reclaimers are operated

manually and the depth of the bucket wheel is determined by monitoring the


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51

CHAPTER 3

reclaimer boom scale reading (yellow line) This makes it difficult to reclaim at a

constant rate

The reason for the high peak surges is due to avalanches on the stockpile

caused by reclaiming on the lower benches without first taking away the top

material The blue line in Figure 34 represents a conveyor scale reading after

the material has passed through a series of transfer chutes It is clear that the

peaks tend to dissipate over time as the peaks on the blue line are lower and

smoother than that on the yellow line

IlmJ

bull I _ bull It bull bull bull bull

--ErI--E--~---h--E=+[J]--EiE ~ J~~~ middot middot -~L I-~f~1-1shyt~=tt~~J~~v5 i ~ ~ ~ ~ ~ i ~ 1 ~ ~ ~ s ~ ------ ~-- - ------ - _ - -------- -- -- - _---- -- -r - --- -_shyp

C)

~ 1r =r=l[=1 -It-1 -- -~ -t= --shy~ _middotmiddot -r middotr middot middot [middot _r _ _ r- middotmiddot rmiddot middotmiddot -r- rmiddot-- middotmiddotmiddot -rmiddot -r-middotmiddot middotr lXgtO middotmiddotmiddotmiddotmiddotmiddotmiddotmiddot[middotmiddotmiddotmiddotmiddotmiddotmiddotlmiddotmiddotmiddotmiddotmiddotmiddotlmiddotmiddotmiddotmiddotmiddotmiddotmiddotmiddotimiddotmiddotmiddotmiddotmiddotmiddotmiddotmiddotr-middotmiddotmiddotmiddot j middotmiddot1middotmiddotmiddotmiddotmiddot1middotmiddotmiddotmiddotmiddotmiddotmiddot1middotmiddotmiddotmiddotmiddot middotlmiddotmiddotmiddotmiddottmiddotmiddotmiddotmiddotmiddotmiddotmiddotjmiddot I~ [ bullbullbullbullbullbullbull [ bullbullbull middotmiddotmiddot1middotmiddotmiddotmiddotmiddotmiddot1middotmiddotmiddotmiddotmiddotmiddotmiddotmiddot1middotmiddotmiddotmiddotmiddotmiddotmiddotmiddot middotmiddotmiddotmiddotmiddotmiddotmiddotmiddoti~middotmiddotmiddotmiddotmiddotmiddotmiddotmiddottmiddotmiddotmiddotmiddotmiddotmiddotmiddotrmiddotmiddotmiddot middotrmiddotmiddotmiddotmiddotmiddotmiddot~middotmiddotmiddotmiddotmiddotmiddotmiddotmiddot1middotmiddotmiddotmiddotmiddotmiddotmiddotmiddotimiddotmiddotmiddot

t) cent

~ i i l i i i i i i i it ~ 8 ~ ~ S l i

~~ Ii ~ ~ g i i ~ 4 1 J yen i

s a e 11 JI as $ $ ~ IS IS e It

Time

-Con~SCO=-E___S~ SCALE

Figure 34 Peak surges experienced during reclaiming operations

347 Other Problem Areas

Some blockages on other chutes at the facility occurred while testing the

stockyard chutes These blockages are also shown in Table 3 where the test


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52

CHAPTER 3

results are discussed and to raise awareness that the bottlenecks on site are not

only caused by problems on the tested chutes

A chute downstream from the stockyards encountered a blockage with fine I

material when the flow rate reached 11 OOb tfh Although this is higher than the

test maximum of 10 000 tfh it still raises concern as to why the chute blocked so

severely that it took approximately two hours to clear

Another bottleneck is the transfer point between the feed conveyor of CV 2 and

the discharge chute on CV 2 This transfer point blocked with fine material at a

peak just below 10 000 tfh It should be even worse with coarse are as

previously discussed Due to the configuration of the head chute spillage of

scraper dribblings is also of great concern The main stream of material

interferes with the flow path of the dribbling material Therefore the carry back

scraped off the bottom of the feeding belt cannot i~ow down the chute and is

pushed over the sides of the chute

The optimisation of transfer chutes in the bulk maferias industry

MN van Aarde

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CHAPTER 3

35 SUMMARY OF TEST RESULTS

Table 3 Results from test programme

Transfer Point Material Tested Test No Peak Capacity Blocked Chute

CV11 CV5 Yes

Fines N 14 10000 tlh No

Fines N 15 10000tlh No

CV 11 CV6 Coarse K 20 9300 tlh No

Fines K 4 10600tlh No

Fines A 19 9633 tlh No

CV31 CV5 Yes

Yes

Yes

Coarse A 17 9427 tlh No

CV31 CV6 Coarse K 7 10195t1h Yes

Coarse K 8 11 000 tlh Yes

CV41 CV5 Coarse A 16 10307 tlh No

No (Mech trip on

CV4CV6 Fines K 10 10815 tlh downstream conveyor)

Coarse K 11 8000 tlh No


No (Feed to CV 2

CV21 CV5 Fines N 13 10 000 tlh blocked)

CV21 Coarse K 1 amp 2 10 153 tlh No

No (Blocked chute on

Fines K 3 11 000 tlh downstream transfer)


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54

CHAPTER 3

Table 3 shows the results obtained from all the tests on the stockyard conveyor

discharge chutes Where possible the same material grade was tested more

than once on the same transfer in order to confirm the repetitiveness of the test

The tests shown in red indicate the transfers that blocked at a flow rate of less

than 10000 tlh

Coarse K and Coarse 0 are noted as the critical materials for blocked chutes

caused by a peak surge Tests with Coarse K and Coarse S where a blocked

chute occurred at just over 10 000 tlh can also be considered as failed tests

This is due to the lack of a safety margin freeboard inside the chute When

analysing the video images a build up can be seen at a flow rate of less than

10000 tlh

Table 3 indicates that the fine material did not cause blocked chutes but it was

seen that it did fill up the chute throat area in some cases Although the coarse

material grades are shown as being least suitable for high flow rates the fine

material should not be underestimated for its ability to cause blockages The

finer materials normally have higher clay contents than the coarse grades and

therefore stick to the chute walls more easily_

36 CONCLUSION

At lower capacities (7 000 tlh to 8 000 tlh) the material appear to flow smoothly

inside the chutes without surging or building up in the chute This flow rate

normally does not cause spillage or skew loading on the receiving conveyor belt

On average as the flow rate approaches 9 000 tlh the material in the chute

throat area starts packing together and finally blocks up the chute

At transfer rates greater than 9 000 tlh the available area inside the chutes is

completely filled up This causes material to build up or surge inside the chute

which eventually results in the chute choking and the inlet flow becomes greater


MN van Aarde

55

CHAPTER 3

than the outlet flow Depending on the volume of the chute the choked state can

only be maintained for a certain period of time If the inlet flow does not

decrease it will cause a blocked chute

Peak surges of up to 10 000 tfh were recorded in most tests which involved a

material surge inside the chute but without the occurrence of a blocked chute trip

Although no blocked chute signal was given in these cases the ability of the

chutes to transfer continuously at flow rates of between 9 000 tfh and 10 000 tfh

is not very reliable

Continuous transfer at flow rates approaching 9 000 tfh seems attainable in most

cases but due to the limited freeboard available in the chute throat area the

chutes will easily become prone to blocking Due to the high peak surges at an

increased maximum reclaim rate the amount of freeboard is critical If the

design criteria of the chute were intended to accommodate these large surges

then all the chutes failed this test This can be attributed to the fact that no

freeboard is left at a maximum reclaim rate of 9 000 tfh

With the background available from the test programme it is clear that further

investigation is required to obtain a solution to these problems All the

information gathered can be integrated and utilised to provide a solution A

possible solution can then be tested against the problems found with the current

transfer chutes


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CHAPTER 4

CHAPTER 4 DYNAMIC CHUTES FOR THE ELIMINATION OF

RECURRING PROBLEMS


MN van Aarde

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CHAPTER 4

41 PREFACE

After completion of the chute test programme the decision was made to improve

the old transfer configuration by installing a dynamic chute The reason for the

dynamic chute is to increase the material speed and decrease the stream cross

sectional area The dead boxes in the older chute slowed the material down and

the restriction on transfer height resulted in the material not being able to gain

enough speed after impacting on the dead boxes

A dynamic chute configuration is investigated in this chapter As the new chute

is fitted within the existing steelwork there are certain constraints that determine

the new configuration All the constraints and limitations discussed in this section

are specific to the facility under discussion

The new chute design basically consists of a hood and spoon which retains the

kinetic energy in the material stream as it is transferred from one conveyor to the

other This will reduce the creation of dust in the chute and help to discharge the

material at a velocity closer to that of the receiving conveyor The new design

does however experience high wear which was not a problem with the old chutes

due to large dead boxes

In order to fit the optimum design of a dynamic chute within the existing structure

some changes are required to the positioning of the feed conveyor head pulley

These changes are necessary to accommodate the discharge trajectory from the

feeding conveyor

The radii of the hood and spoon are specified in such a way that the impact wear

is reduced significantly In addition both the hood and spoon are fitted with a

removable dead box section in the impact zones The incorporation of these

sections makes this chute revolutionary in the sense of ease of maintenance


MN van Aarde

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CHAPTER 4

This new chute addresses all problems identified at the facility and aims to

eliminate most of them

Tests were carried out to identify worst case materials for flow and wear

Different liner materials were tested for both flow and wear conditions The

outcome of these tests is used as the basis for the design of a new chute As

different conditions for flow and wear inside the chute exist different liners are

investigated for each section inside the chute

42 CONSIDERATION OF THE EXISTING TRANSFER POINT CONSTRAINTS

The stockyard consists of four stacker reclaimers and several transfer points

feeding onto the two downstream conveyors resulting in a very intricate system

This system has numerous requirements which need to be addressed when

considering a new transfer chute configuration The transfers under discussion

are situated at the head end of the stockyard conveyors

MOV1NG HEAD OER MOvm poundAD OVER CVI6 CVIS

t4CLIE SECTION

PURGING POSmON

Figure 35 Stockyard head end layout

The design of a new transfer chute configuration is restricted to a certain extent

by the existing structures on site Figure 35 provides an overall view of the

existing steelwork at the head end of the stockyard conveyor This existing steel

structure can be modified to suit a new configuration but does have some fixed


MN van Aarde

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CHAPTER 4

constraints A good example of these constraints is the transfer height between

the stockyard conveyor and the downstream conveyors CV 5 and 6

On both sides of the stockyard conveyor stockpiles of ore can be reclaimed and

deposited onto the conveyor This facility allows a certain travel for the stacker

reclaimer along the stockyard conveyor for the stacking and reclaiming of

material The most forward position of the stacker reclaimer is at the beginning

of the incline section of the stockyard conveyor As previously explained any

curvature in a conveyor requires a certain minimum radius When the transfer

height is raised the radius constraints on that curvature in the stockyard

conveyor will reduce stockyard space This means that the storage capacity at

the facility will be greatly diminished

I ~

j

Figure 36 Dimensional constraints on the existing transfer configuration

The ideal is to stay within the eXisting critical dimensions as shown in Figure 36

As functionality of the chute dictates the chute configuration these dimensions

can be modified within certain constraints These critical dimensions on the

existing configuration are


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CHAPTER 4

bull Centre of receiving belt to centre of the head pulley 800 mm

bull Bottom of receiving belt to top of the head pulley 4048 mm

The head pulley can however be moved back a certain amount before it

becomes necessary to change the entire incline section of the stockyard

conveyor As the moving head moves forward and backward there are idler cars

trailing behind the moving head carriage as shown in Figure 35 The purpose of

these idler cars is to support the belt when the moving head is feeding onto

CV 6 or when it is standing in the purging position

43 DESIGN OF THE CHUTE PROFILE

431 Design Methodology

Proven standard methods for the functional design of the chute are used These

hand calculation methods are based on the Conveyor Equipment Manufacturers

Association (CEMA) standard as well as papers from Prof AW Roberts These

are typically calculations for determining the discharge trajectory optimal radius

of the hood and spoon as well as the velocity of material passing through the

chute

In addition to standard methods of carrying out conceptual flow design it is

supplemented by the use of Discrete Element Modelling (OEM) simulation

software This is done to visualise the flow of material through the chute

Results from standard calculation methods are compared to the outputs of the

OEM simulations to confirm both results Chapter 5 will focus on the use of

Discrete Element Modelling for the design and verification of chute concepts


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CHAPTER 4 -__-----__---_----------shy

432 Design Development

Figure 37 shows the concept of the hood and spoon chute for a 90deg transfer as

required by the facility layout The decision to opt for a hood and spoon chute is

based on trying to retain the material velocity when transferring material from the

feeding conveyor to the receiving conveyors Retention of material velocity is

critical as the transfer height is restricted The overall facility constraints for

design are as follows

bull Feeding belt speed - 45 ms

bull Receiving belt speed - 45 ms

bull Transfer height - 401 m

bull Belt widths -1650 mm

bull Maximum material throughput -10000 tlh

As this is a retrofit of an existing facility some of the facility constraints cannot be

changed This forms part of the design development as it steers the design in a

certain direction Due to the fact that the transfer height cannot be changed the

chute profile will be dependent on the transfer height restriction

The optimisation of transfer chutes in the bulk matefials industry

MN van Aarde

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CHAPTER 4

START-UP CHrrlE

DRlBBIlNG CHUTE

Figure 37 Hood and spoon configuration for the 90 transfer

The optimum solution for the correct chute profile in this situation would be to

move the head pulley back far enough This should be done so that the hood

can receive the material trajectory at a small impact angle and still discharge

centrally onto the spoon However the head pulley can only be moved back a

certain amount Any further movement will require changes to the structure of

the feeding conveyor incline section

As the stockyard conveyors feed onto two receiving conveyors the head pulley

of the stockyard conveyors is situated on a moving head rail car This enables

the conveyor to discharge either on CV 5 or CV 6 as shown in Figure 25

Taking the movement of the head pulley into account the moving head rail car

can be shortened by 1000 mm in order to move the head pulley back As stated

in the preface all changes are distinctive to this facility alone However it is

important to be aware of the consequences of every modification


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CHAPTER 4 -__----- ------shy

433 Determination of the Profile

An important of the hood and spoon design is to ensure a

discharge from the hood onto the centre of the spoon The is

determined using equation (1) in section 24 Although various material

are transferred it does not have a significant effect on the calculated trajectory

the bulk properties of the materials are very similar It is however important

to the material which will transferred obtain the flow angles and wear

This information the will be

the Liner selection for this case study is discussed in Appendix A

After the trajectory has been determined the hood radius can determined by

using equation (2) As head pulley can move 1 000 mm backward the

possible hood radius was determined to 2 577 mm This hood radius is

VIU(I(1 to produce the wear on the zone in chute

The impact angle at this radius is 11 which is less than the maximum

allowable limit of 20

The hood radius is chosen to as close as possible to radius of curvature of

the material trajectory The point where the hood radius and the trajectory radius

cross is known as the impact point In to determine the velocity

point in hood the at is required on the

hood from the horizontal where the material impacts and to slide down the

hood surface

In this case the position impact hood is at 558r from the horizontal

In to determine the velocity this angle e is used as starting

point in (3) obtain a complete velocity profile angle from where

the material impacts hood is decreased in increments 5 up to the

discharge point which is normally 0

The optimisation chutes in the bulk materials industry

MN van Aarde

64

-----

CHAPTER 4

Hood Velocity Profile

70

--- --~ 6 0

5 0

40 ~_

~ 30 g --- a 20 gt

10

00

60 50 40 30 20 10 o Theta (Position inside the hood)

Figure 38 Hood velocity profile

The spoon radius is determined in such a way that the wear at the point of impact

is kept to a minimum At the same time the horizontal component of the material

exit velocity is as close as possible to the receiving belt speed Firstly the

assumption is made that the initial velocity of material in the spoon is equal to the

exit velocity of material from the hood This yields a spoon entry velocity of

633 ms and can also be seen from Figure 38

By reiterating various radii for the spoon the optimum exit velocity Ve can be

obtained These radii are selected according to the available space in which the

spoon must fit and also to produce the smallest impact angle for material

discharging from the hood This table is set up to display the different exit

velocities at various spoon radii The exit velocity is also dependent on the exit

angle which is determined by the length of the spoon arc In this case the spoon

radius is chosen as 3 575 mm An exit angle of 38deg from the horizontal yields an

exit velocity closer to the receiving belt speed


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CHAPTER 4

Spoon Velocity Profile

67

66

65

S 64 amp0 g 6 3

V

v-shy ~ ~

ii ~ gt 62

61 I I 60

o 10 20 30 40 50 60

Theta (position inside the spoon)

Figure 39 Spoon velocity profile

Taken from the origin of the spoon radius the material position in the spoon at

discharge is sr The selection of this angle is guided by the geometry of the

chute and surrounding structures This angle is then used to calculate the exit

velocity as shown in Figure 39 At this point the discharge angle relative to the

conveyor angle is 38deg Ve is then determined to be 6087 ms with a velocity

component of 479 ms in the direction of the belt This value is 618 higher

than the belt speed of 4S ms which is acceptable as it is within the allowable

10 range of variation Minimal spillage and reduced wear on the receiving

conveyor is expected

Both the hood and spoon have a converged profile This is done in order to

minimise spillage and ensure a smooth transfer of material from the hood to the

spoon and from the spoon to the receiving conveyor The converged profile

starts out wide to capture any stray particles and converges to bring the material

particles closer together at the discharge This profile does not influence the

transfer rate of the chute as the stream of material through the chute is no more


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66

CHAPTER 4

compact than the material on the conveyor belt before and after the transfer

chute

44 INCORPORATING ADEAD BOX IN THE IMPACT AREAS

In chapter 1 reference is made to a chute design utilising pipe sections with a

rounded profile The flat back plate is chosen instead of a rounded pipe type

section to house the honeycomb dead box configuration It would be possible to

fit the honeycomb into a rounded back section but manufacturing and

maintenance would be unnecessarily difficult and expensive

Furthermore the cross section profile of the chute shows three sliding surfaces

as shown in These surfaces consist of the back plate two vertical side plates

and two diagonal plates This is done in order to increase the angle between

adjoining plates so that the probability of material hanging up in the corners is

reduced This helps to alleviate the risk of experiencing blocked chutes

Figure 40 Chute cross section


M N van Aarde

67

CHAPTER 4

441 Honeycomb Wear Box in the Hood

A honeycomb or wear box is incorporated into this chute configuration in order to

further minimise wear in the hood and spoon The honeycomb configuration is

clearly shown in and is typical for both the hood and spoon Reduced wear will I

be achieved as impact and sliding will take place on the basis of material on

material flow Ore is captured inside the honeycomb pockets which protects the

ceramic lining in the section of the honeycomb and creates another sliding face

made of the material being transferred The ribs in the wear box do not protrude

from the sliding face of the chute and therefore do not interfere with the main

stream flow of material

Positioning of the honeycomb is critical as the point of impact on the hood needs

to be on the honeycomb This is required in order to assure that the highest

material impact is absorbed by a layer of static material inside the honeycomb

and not the chute liners All the basic steps for designing a normal hood and

spoon chute are followed Firstly the angle at impact (8e) is calculated to

determine where the trajectory of material will cross the radius of the hood This

shows the position of the impact point on the hood Figure 20 indicates where 8e

is calculated As previously stated the angle at impact for this situation is

558r This is calculated using [33]

e = tan- I ( 1 ) (5)

C Ii

And y is defined by equation 1

This gives an indication as to where the honeycomb should be situated in order

to capture the material impacting the hood fully A flow simulation package can

also be used to determine the position of this honeycomb structure shows an

opening for the honeycomb which starts at 40deg clockwise from the vertical This


MN van Aarde

CHAPTER 4

means that there are almost 16deg of free space in the honeycomb to ensure that

the material will always impact inside the wear box

There is no set specification as to the size of this free space This is just to

accommodate any surges of mat~rial on the feeding conveyor As discussed in

Chapter 3 due to avalanches while reclaiming from the stockpiles material

surges on the conveyors is a reality

Figure 41 Honeycomb wear box positioning

illustrates exactly where this wear box is situated on the back plate of the hood

This configuration is very similar to that of the spoon as both wear boxes only

cover the width of the flat back plate of the hood and spoon The reason for this

is that most of the material impact and mainstream flow strikes the back plate


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CHAPTER 4

WEAR BOX

Figure 42 Wear box in the hood section

All the horizontal ribs of the honeycomb are spaced 5deg apart and there are 5

vertical ribs following the converging contour of the hood as shown in Spacing

of the ribs depends largely on the maximum lump size handled by the transfer

In this case the largest lumps are approximately 34 mm in diameter The idea is

to get as many dead boxes into the honeycomb as possible These small

cavities should however be large enough to capture a substantial amount of ore

inside


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CHAPTER 4 ----_----------------shy

Figure 43 Spacing arrangement of honeycomb ribs inside the hood

The two vertical liners on the edges of the honeycomb are only 65 mm high while

the rest of the vertical liners are 120 mm high This is done so that the flat liners

in the chute surface can overlap the edge liners of the honeycomb An open

groove between the tiles along the flow of material would cause the liners to be

worn through much faster than in normal sliding abrasion conditions Due to the

high wear characteristics of the ore all openings between tiles should be kept out

of the mainstream flow

All the ribs in the honeycomb are 50 mm thick and vary in depth The vertical

ribs protrude the horizontal ribs by 30 mm in order to channel the flow These

vertical ribs are all flush with the surrounding tiles on the flat sliding surface of the

hood All the pockets of the wear box are 120 mm deep measured from the top

of the vertical ribs Again dimension is dependent on the maximum lump size

handled by the transfer There are no specifications as to the relation between

the pocket size and the lump size These dimensions were chosen to be

approximately 4 times the lump size Computer simulations can be used to test

the feasibility of this concept while commissioning of the equipment will ultimately

show whether this method works


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CHAPTER 4 ------------_ -- - ---------------shy

442 Honeycomb wear box in the spoon

The honeycomb wear box in the spoon has the same configuration as in the

hood It also covers the entire width of the back plate and fully accommodates

the material impacting on the spoon from the hood The entire spoon is broken

up into three sections and the honeycomb wear box is situated in the back

section as shown in

Figure 44 Wear box in the spoon section

With almost the same configuration as the hood the spoon also has a corner

liner to ensure a continuous lined face between the flat surface liners and the

honeycomb ribs The detail of these liners and ribs are shown in A 90deg transfer

with a hood and spoon chute means that the stream received by the spoon is

narrower and longer than the stream received by the hood This is caused when

the material takes the shape of the hood before it is discharged into the spoon

The converged configuration causes the stream to flatten against the sliding

surface in the chute


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CHAPTER 4

Due to the spoon honeycomb being a bit narrower than the hood there are only

three vertical ribs The number of ribs had to be reduced to be able to

accommodate the preferred cavity size of the honeycomb boxes These ribs now

form two channels in which the stream of material can be directed

Figure 45 Liner detail of the spoon honeycomb wear box

As shown in there is a 3 mm gap between the honeycomb section and the chute

plate work This is to ensure that the honeycomb section can be easily removed

for maintenance on the liners All the edges of the liners have rounded corners

to reduce stress concentrations which can cause rapid liner failure

45 DESIGNING THE CHUTE FOR INTEGRATION WITH SYSTEM REQUIREMENTS

The arc length of the spoon back plate is longer and closer to the belt in order to

ensure a smooth transfer of material from the chute to the receiving conveyor A

small gap of 75 mm is left between the bottom of the spoon and the receiving

conveyor Due to the fact that material can also be fed from another upstream


MN van Aarde

73

CHAPTER 4

stockyard conveyor this configuration will not be suitable This means that the

gap of 75 mm is not enough to allow material to pass underneath the chute

To accommodate this situation the spoon is split into different sections where the

bottom section lifts up to make room for material from behind In the raised

position the gap between the chute and the belt is 450 mm When the lower belt

is loaded to full capacity the material height is 380 mm This means that the

clearance to the belt in the non operational position is sufficient and show the

operational and non operational positions of the spoon

T -t t----~r_-+-wtIY1shy

Figure 46 Spoon in the operational position


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74

CHAPTER 4

Figure 47 Spoon in the non operational position

This section is a discussion on how this new transfer chute configuration should

be operated in order to comply with the facility requirements The bottom section

of the chute can be lifted out of the way of material from behind on the receiving

conveyor Therefore a control philosophy is required for this movement

Referring to Figure 25 positions A and B indicate where these new chutes will be

installed As previously stated position C is the purging or dump position and

show the actuated spoon section in the operating and non operating positions

The conditions for these positions are explained as follows

46 CONCLUSION

With the consideration of all the facility constraints and a conceptual idea of what

the transfer configuration should look like the design can be optimised When

the feeding belt velocity is known the material trajectory and optimum chute

radius can be determined This radius and the radius of the spoon must then be

corrected to comply with the facility constraints but still deliver the required

material transfer rate


MN van Aarde

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CHAPTER 4

With the high cost implications of regular maintenance intervals on chute liners

and facility downtime a honeycomb structure is incorporated into the high impact

areas The purpose of this honeycomb structure is to form small pockets similar

to dead boxes in order to promote material on material flow This increases the

lifetime of the chute liners and reduces maintenance intervals

This specific transfer chute splits up easily into separate sections and will help to

simplify maintenance The bottom section of the chute is actuated to move up

and down depending on whether the chute is in operation or not This will ensure

optimum transfer of material while in operation and provide sufficient clearance

when not in operation This is again guided by the facility requirements

In the design of all the transfer chute components the physical properties of the

ore should always be considered This determines the chute profile in terms of

flow angles and liner selection With maximum material flow ability high

resistance to sliding abrasion and reduced maintenance cost in mind 94

alumina ceramics is the liner of choice This is only in the main flow areas of the

chute For the dribbling chute a polyurethane liner is used to promote the flow of

this sticky material


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CHAPTER 5 TESTING AND VERIFICATION OF THE NEW SOLUTION

- middotSmiddotmiddotmiddotmiddotmiddotmiddotmiddotmiddotmiddot-middotl~Oi


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51 PREFACE

Although hand calculations have been a proven method of design for many

years it is important to verify any new chute concept before fabrication and

implementation Confirming the concept can save time and money as it reduces

the risk of on-site modifications Hand calculations only supply a two

dimensional solution to the problem which does not always provide accurate

material flow profiles

In recent years a few material flow simulation packages have been developed to

aid the design of material handling equipment The use of software packages

can be beneficial to the design process as it gives a three dimensional view of

the material behaviour in the chute This means that changes to the chute

concept can be made prior to fabrication

It is however important to verify that the solution obtained from the software

package is an accurate reflection of actual design model Therefore the material

being handled should be thoroughly tested to obtain the correct physical

properties required to obtain an accurate simulation result

The use of material flow simulation software does not replace the necessity for

hand calculations All the basic steps should still be done to derive a conceptual

chute configuration Material flow simulation software should be used as a

complimentary tool to analytical hand calculations in the design process

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52 SELECTING A TEST METHODOLOGY

Traditionally transfer chutes were designed by using basic analytical calculations

and relying on empirical data from past experiences with other chutes Mostly

these analytical methods only cater for the initial part of the chute such as the

parabolic discharge trajectory It is difficult to determine what happens to the

flow of material after it strikes the chute wall [34]

Two methods of verification were usually applied to evaluate a new transfer

chute configuration Trial and error can be used but obviously this is not desired

due to the high cost implications A second method is to build a small scale

model of the chute in which tests can be carried out before a final design can be

adopted This physical modelling is however time consuming and

expensive [34]

Granular or particulate materials are composed of a large number of loosely

packed individual particles or grains The flow of such granular materials forms

an intricate part of the materials handling industry Small reductions in energy

consumption or increases in production can have great financial advantages

Therefore significant efforts are put into improving the efficiency of these

facilities The important role of numerical simUlations is becoming more evident

in these optimisation procedures [35] Due to these efforts this technology is

becoming more powerful and is easy to use as a verification method for transfer

chute designs

The behaviour of bulk material particles is unique in the sense that it exhibits

some of the properties associated with the gaseous liquid and solid states of

matter The granular state of bulk materials cannot be characterised by anyone

of these states alone The research that captures the contact between individual

particles in an explicit manner is known as discrete element methods (OEM) [36]


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In basic terms OEM explicitly models the dynamic motion and mechanical

interactions of each body or particle as seen in the physical material flow It is

also possible to obtain a detailed description of the velocities position and force

acting on each particle at a discrete point during the analysis This is achieved

by focusing on the individual grain or body rather than focusing on the global

body as is the case with the finite element approach [36]

Figure 48 illustrates two examples of how this OEM software can be applied

Obviously the flow characteristics differ between the applications shown in Figure

48 This is however catered for by the mathematical simulation of each particle

collision

Figure 48 Flow analysis examples a) separation and screening b) hoppers feeders 36]

Continuous improvements in the performance of computing systems make OEM

a realistic tool for use in a wide range of process design and optimisation

applications During the last 20 years the capabilities of OEM have progressed

from small scale two dimensional simulations to much more complex 3D

applications The latest high performance desk top computers make it possible

to simulate systems containing large numbers of particles within a reasonable

time [37]


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According to the institute for conveyor technologies at the Otto-von-Guericke

University of Magdeburg in Germany using OEM for bulk solid handling

equipment provides [38]

bull A cost effective method of simulating the utility of materials handling

equipmentshy

bull Precise control over complicated problem zones eg transfer chutes

redirection stations and high wear areas

bull The possibility to integrate processes in one simulation such as mixing and

segregation

bull The possibility to involve the customer more extensively in the design

process

bull An advantage in the market due to attractive video sequences and pictures

of the simulation

bull The possibility to prevent facility damages and increase the efficiency of

conveyor systems extensively

As a good example of the advantages of the discrete element method the

University of Witwatersrand in Johannesburg did studies on rotary grinding mills

The university studies have shown that the OEM qualitatively predicts the load

motion of the mill very well The improved knowledge of the behaviour of mills

can therefore increase the profitability of mineral processing operations [39]

This material handling equipment is generally costly to operate and inefficient in

the utilisation of energy for breakage In order to understand the behaviour of

mills better the OEM method is increasingly being applied to the modelling of the

load behaviour of grinding mills These results indicate that this method can be

applied successfully in the bulk materials handling industry

The apUmisatian af transfer chutes in the bulk materials industry

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Another example where this technology has been used with great success is with

the design of a new load out chute for the Immingham coal import terminal in

Britain By simulating the flow with a OEM package the designers were aided in

the fact that they were supplied with a quantitative description of the bulk solid

movement through the chute In the opinion of Professor Franz Kessler

(University of Leoben) the Discrete Element Method provides the engineer with

unique detailed information to assist in the design of transfer points [3]

These simulation packages are at the moment very expensive and not widely

used in transfer chute design It can be anticipated that the utilisation of these

packages will increase as the technology improves and the cost of the software

goes down [40] To get the best value out of the simulation it is important to

compare simulation packages and select the one most suitable to the complexity

of the design

Fluenttrade is a two dimensional computational fluid dynamics (CFD) software

package which can also be used as a chute design aid through the simulation of

material flow It must however be noted that this is not a OEM simulation

package This software package simulates the flow of material by considering

the material particles as a liquid substance The output of the simulation is the

same as can be seen in the example of Figure 49 The colours in the simulation

represent the average particle spacing [40] Due to the fact that this package

can at this stage only deliver two dimensional simulations it is considered

inadequate to perform detailed simulations on the intricate design piscussed in

this dissertation

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COnroUf Votume t-~bn 01 ( 00 frlm~2 5000amp1 00) ~gtJ C3_2002 fLUENT 60 (2lt1 9 940 n 1Mgt u ody)

Figure 49 Simulations results from Fluenttrade [40]

The Overland Conveyor Company provides another alternative to the Fluent

software package Applied OEM is a technology company that provides discrete

element software to a variety of users in the bulk materials industry Bulk Flow

Analysttrade is an entry level package that they provide This package is very

powerful in the sense that it can accurately predict flow patterns depending on

the accuracy of the inputs An example of this is shown in Figure 50 It also has

the capability to show material segregation dynamic forces and velocities [41]

Figure 50 Simulation results from Bulk Flow Analysttrade [41]


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OEM Solutions is a world leader in discrete element modelling software They

recently announced the release of the latest version of their flow simulation

package called EOEM 21 This package can be used to simulate and optimise

bulk material handling and processing operations [41] Oue to the capabilities of

this software package it is a very attractive option for designing transfer chutes

With the development of EOEM 21 OEM Solutions worked in collaboration with

customers in the Bulk Handling Mining and Construction Pharmaceutical

Chemical and Agricultural sectors This enables the end users to perform more

sophisticated particle simulations specific to their unique applications Also

incorporated into this package is the ability and flexibility to customise and

personalise advanced particle properties [42]

This specific package has been proven successful by industry leaders Martin

Engineering (Neponset Illinois) is a leading global supplier of solids handling

systems This company continues to expand their use of EOEM software in

design optimisation and development of bulk materials handling products These

optimisation and development actions include all aspects of conveyor systems

and transfer points for numerous industrial sectors [43]

There are several other OEM simulation packages such as ESYS Particle

Passage-OEM and YAOE However none of these software packages seem be

major industry role players in the discipline of chute design although they might

have the capability In adjudicating the three big role players in bulk material flow

simulation packages there are a few factors taken into consideration It appears

thatthe advantages of 30 capabilities are non negotiable Therefore Fluenttrade is

not really a consideration From the literature review of the Bulk Flow Analysttrade

and the EOEM packages it seems that these two will provide more or less the

same performance It does seem however that the EOEM software is a bigger

role player in various industries Due to the possible future capabilities of EOEM The optimisation of transfer chutes in the bulk materials industry

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through its association with numerous industries this simulation package is the

software of choice

In order to retrofit or design a new transfer point with the aid of the selected OEM

software package there are a few steps that a designer must follow to gain the

full benefit of this tool [36]

1 An accurate 3D or CAD representation of the new or old transfer chute

must be rendered

2 Identify restrictions and limitations in terms of chute geometry and

manufacturing

3 Identify desired design goals (Le dust emissions flow restrictions etc)

4 Identify representative material properties and particle descriptions

5 In case of a retrofit make design changes to chute geometry with CAD

6 Simulate the performance of the new design using OEM software

7 Evaluate results obtained from the simulation (reiterate steps 5 6 and 7)

8 Perform and finalise detail design steps

9 Manufacture

10 Installation

The above mentioned steps found in references [6] and [36] only provides

information regarding retrofitting or designing chutes with the aid of OEM

Although it is a powerful design 1001 the design process should not discard the

use of analytical hand calculation~ Some of the most important design decisions

regarding chute profiles are made with analytical hard calculations such as

plotting the material trajectorY

53 DETERMINATION OF MATERIAL PROPERTIES

The discrete element method is a promising approach to the simUlation of

granular material interaction The accuracy of the outcome of the simulation is


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however dependent upon accurate information on the material properties and

input parameters [44] These inputs basically consist of the following

fundamental parameters size and shape factors bulk density angle of repose

cohesion and adhesion parameters and restitution coefficients [45]

The determination of most of these parameters are explained and defined in the

following paragraphs The parameters that are changed in the simulation

according to the reaction of the flow are not discussed and are typically

parameters such as the internal coefficient of friction between a number of

particles A collaborated effort by the bulk handling industry aims to find ways in

which all parameters can be accurately determined through scientific methods

This has however still not been achieved The objective is to achieve a realistic

representation and therefore some parameters are altered in the simulation

It is important to note that the computation time increases as the particle size

becomes smaller and the amount of particles increase In most granular flow

problems the characteristics of the material stream are largely determined by

particles greater than 10 - 20 mm in size [45] Therefore in order to reduce

computation time the selected particle size for simUlations should be the same

as the largest particles handled by the facility namely 34 mm diameter

Although fines have a higher internal friction coefficient and more cohesiveness

these properties can be averaged into the input parameters to obtain the same

overall effect [45] Therefore only a single particle size is used in the simulation

and the properties optimised to obtain the same result under actual operating

conditionsmiddot Some of the material properties can be easily obtained from the

facility The rest of the properties are obtained from tests carried out by expert

conSUltants in this field

The size factor and bulk density are obtained from the facility Materia tests

carried out by external consultants provide the coefficient of friction and also the The optimisation of transfer chutes in the bulk materials industry

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wall friction angle This is the angle at which the material will start to slide under

its own mass To determine these material properties the external consultants

normally use sophisticated and expensive equipment Data gathered from these

tests are used for the hand calculation of the chute profile The angle of repose

can normally be observed from a stockpile and is the angle that the side of the

stockpile makes with the horizontal

For the OEM simulation the coefficient of friction is one of the main determining

factors of the wall friction angle Data provided by the material tests can not be

used as a direct input into OEM In the software package the coefficient of

friction is represented by a factor between 0 and 1 The material test data can

however provide some insight into where on this scale the factor is This factor

can be derived from a few small simulation iterations as there is no method of

direct conversion between the test result data and the OEM input

To determine this factor a plate is modelled with a single layer of particles This

plate is then rotated within the simulation at approximately 2deg per second As

soon as the particles begin to slide the time is taken from which the angle can be

calculated This process is repeated with different friction coefficients until the

correct wall friction angle is obtained After the coefficient of friction factor is

determined between the particles and the chute wall the material restitution

factor and coefficient of internal friction can be obtained

The restitution factor is obtained by measurirtg the rebound height of a particle

when it is dropped from a certain height This is usually difficult to determine due

to the variation in shape of the material particles If the particle lands on a

surface it rarely bounces straight back up Therefore the test is repeated

numerous times and an average is taken to obtain the final result

Coefficient of internal friction is a property that describes the particles ability to

slide across each other A simUlation is set up to create a small stockpile of The optimisation of transfer chutes in the blJlk materials industry

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material particles The angle of repose can be obtained by measuring the

average apex angle of the stockpiles In this simulation the coefficient of internal

friction and restitution factors are iterated This is done in order to simulate the

accurate behaviour of particles falling onto the stockpile and forming the correct

angle of repose Figure 51 shows what this simulation typically looks like

Figure 51 Determination of material properties for an accurate angle of repose

54 VERIFICATION OF THE SELECTED TEST METHODOLOGY FOR THIS

APPLICATION

The best verification is to compare the simulation results with an actual material

flow situation Therefore a comparison is made between the actual flow in the

existing transfer configuration and the simulation of this same transfer This is

also a good test to see if the parameters changed in the simulation were done

correctly

During the chute test programme CCTV cameras were installed in the problem

transfer chutes at the facility The cameras are positioned to provide an accurate

view of the material flow behaviour inside the chutes As explained in Chapter 3


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the behaviour of the material flow inside the chutes changes with the variation of

ore type

Due to the fact that only 34 mm diameter particles are used in the simulation a

test using coarse ore was chosen for the verification of the simulation

Therefore test 12 is used as reference for the verification In this test coarse S

with the particle size distribution between 28 mm and 34 mm was used at the

transfer from CV 3 to CV 5

Figure 52 shows an image taken from the CCTV camera inside the transfer chute

between CV 3 and CV 5 The red line indicates the top of the chute throat

opening and the yellow arrows show the top of material flow This screen shot

was taken at a flow rate of 10 000 tlh It can be deduced from this view and the

chute test work that the chute is choking at a throughput rate of 10 000 tlh

Figure 52 Actual material flow with coarse S at 10000 tIh

The transfer chute from Figure 52 was modelled in CAD and the model imported

into the discrete element package EDEM All the material input parameters as

discussed in section 53 were used in the simulation 10 000 tlh was used as the


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flow rate parameter in an attempt to simulate and recreate the situation as shown

by Figure 52

Test 12 of the chute performance tests gave the following results which can be

compared to the EDEM simulation

bull Chute started to choke rapidly at 10 000 tlh

bull Slight off centre loading onto the receiving conveyor CV 5

bull A lower velocity layer of material close to the discharge of the chute

bull Material roll back on the receiving conveyor due to significant differences in

the velocity of the material flow and the receiving conveyor

Off-centre loading

L

Figure 53 Material flow pattern through the existing chute


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Flow restricted in this area

Low velocity layer

Low discharge velocity rollback

Figure 54 Cross sectional side view of material flow through the existing chute

Figure 53 shows the material flow pattern in the existing chute where the thick

red arrows indicate the direction of flow The legend on the left of the figure

indicates the material velocity in ms Slow flowing material is shown in blue and

the colour turns to red as the material velocity increases Slight off centre

loading onto the receiving conveyor CV 5 can be seen from Figure 53 This

correlates well with the actual observations during the physical testing of this

transfer point

Figure 54 shows the more determining factors for correlation between actual flow

and simulated flow where the legend on the left indicates the material velocity in

ms This is a cross sectional view through the centre of the chute From this

view a build up of material can be seen in the chute throat area The slow

flowing material on the back of the chute also helps to restrict the flow Due to

the fact that the material speed at the discharge of the chute is much slower than

the receiving belt speed a stack of turbulent flowing material is formed behind

the discharge point on the receiving conveyor


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There is a good correlation between the simulated and actual material flow

pattern The simulation method can therefore be considered as a valid alternate

or additional method to standard analytical chute design Attention should be

given though to the input of material properties in order to obtain a realistic result

55 VERIFICATION OF NEW CHUTE CONFIGURATION AND OPTIMISATION OF THE

HOOD LOCATION

After establishing that the OEM is a reliable design and verification tool the new

transfer chute configuration can be simulated Firstly this configuration is

modelled without the honeycombs inside the hood and spoon This is done in

order to verify the material flow pattern and velocity through the hood and spoon

Results obtained from this simulation can then be compared to the hand

calculation results An iterative process is followed with simulations and hand

calculations to obtain the best flow results The simulation results are shown in

Figure 55 and Figure 56

I

L

Figure 55 Material flow through hood at 10 000 tIh


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Figure 56 Material flow through spoon at 10 000 tlh

The hood velocity profile shown in Figure 38 gives the same result as obtained

from the DEM simulation The calculated hood exit velocity is 633 ms This is

the same result obtained from the simulation and shown by the red colouring in

Figure 55 As the material enters the spoon it is falling under gravity and

therefore still accelerating At impact with the chute wall it slows down and exits

the spoon with approximately the same velocity as the receiving conveyor

Figure 56 shows the material flow through the spoon section This can also be

compared to the spoon velocity profile in Figure 39 The behaviour of the

material inside the spoon as shown by the simulation correlates with the results

obtained from the hand calculations This is another indication that with accurate

input parameters the DEM can be used as a useful verification tool


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Skew loading into spoon

Slower material

L

Figure 57 Determination of the optimum hood location

The hood is supported by a shaft at the top and can be moved horizontally This

function is incorporated into the design in order to optimise the hood location

during commissioning of the transfer chute It is critical to discharge centrally into

the spoon in order to eliminate skew loading onto the receiving conveyor

Figure 57 illustrates the effect that the hood location has on material flow When

comparing the flow from Figure 55 to the flow in Figure 57 it is clear that skew

loading is a direct result of an incorrect hood position The circled area in Figure

57 illustrates how the flow reacts to the incorrect hood location

Material is discharged to the right side of the spoon which causes a slight buildshy

up of material on the left This causes the material to flow slightly from side to

side as it passes through the spoon Figure 57 indicates that the material to the


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CHAPTERS ----------------- -------___ _--shy

right at the spoon discharge is slightly slower than the material on the left This is

a clear indication of skew loading onto the receiving conveyor

The material flow pattern in Figure 55 is symmetrical and therefore will not

cause skew loading The OEM can give a good indication of the required hood

setup before commissioning However adjustments can still be made during the

commissioning process The tracking of the receiving belt should give a good

indication of when the hood is in the optimum position

56 EFFECT OF THE HONEYCOMB STRUCTURE IN HIGH IMPACT ZONES

The purpose of the honeycomb dead box structure in the high impact zones is to

capture material inside the pockets and induce material on material flow This

requires that the material inside the honeycombs should be stationary while the

main stream material flow moves over the dead boxes OEM can therefore be

set up in such a way that the material velocities can be visualised inside the

chute

In Chapter 4 the logic of how this honeycomb should be structured and

positioned was discussed The simulations shown in Figure 58 and Figure 59

illustrate how a OEM pack~ge can also be used to determine the positioning of

these honeycomb structures Impact points in the hood and spoon must be

inside the honeycomb in all situations of flow inside the chute The spacing of

dead box pockets can be altered to ensure that a continuous layer of stationary

material is formed in the honeycomb area Various geometries for this

honeycomb structure can be simulated with OEM to obtain the best results


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Large radius hood

Hood honeycomb box to minimise wear in impact

Vertical discharge from hood centralising flow on

belt

L

Figure 58 Material behaviour through hood

Spoon

Spoon honeycomb box to minimise wear in impact area

Improved spoon discharge flow

Figure 59 Material behaviour through spoon


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The legends on the left of Figure 58 and Figure 59 indicate the material velocity

in ms Dark blue indicates stationary material and bright red indicates a

maximum material velocity of 8 ms Using this information the functionality of

the honeycomb dead boxes can now be analysed The velocity of the material

captured by the dead boxes is indicated as dark blue This means that all the

material in the dead boxes is stationary

With the result obtained from the OEM simulation it is clear that material on

material flow will be induced by the honeycomb dead boxes The pockets of the

honeycomb capture the material and will therefore have reduced wear in the

high impact areas This material on material flow does however induce a

coarser sliding surface than the smooth ceramic liner tiles Due to the high

velocity of material through the chute the effect of the coarser sliding surface is

however minimised

58 CONCLUSION

The Discrete Element Method is proven to be a successful design and

verification tool in the bulk materials industry This method is used widely in the

global bulk materials industry The successful outcome of the OEM simulation is

however dependent on the correct material input parameters Some of these

parameters are readily available from the facility that handles the material The

rest of the parameters can be determined by setting up simple test simulations

with OEM

To verify that the OEM simulation is a correct indication of the actual condition

the simulation is compared to CCTV images taken from the same transfer chute

The results show that the OEM simulation does provide a true reflection of the

actual material flow through the transfer chute Therefore the same material

input parameters can be used to simulate the new transfer chute configuration


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From the simulations done on the new transfer chute configuration the effect of

the honeycomb dead boxes can be examined These simulation results show

that the honeycomb dead box configuration is effective in capturing material

inside the honeycomb cavities This results in material on material flow and

reduces impact abrasion on the ceramic chute liners

Results obtained from the OEM simulation of the new transfer configuration are

compared to the hand calculation results This comparison indicates that the

material velocity calculated in the hood and spoon correlates well with the

material velocity calculated by the OEM The overall results obtained from

simulating the new transfer chute configuration have been shown to provide a

true reflection of the actual flow through the chute


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CHAPTER 6

CHAPTER 6 CONCLUSIONS AND RECOMMENDATIONS


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61 CONCLUSIONS AND RECOMMENDATIONS

Bulk materials handling is a key role player in the global industrial industry

Within this field the industry faces many challenges on a daily basis These

challenges as with any industry are to limit expenses and increase profit Some

of the limiting factors of achieving this goal in the bulk materials handling industry

are lost time due to unscheduled maintenance product losses due to spillage

andhigh costs incurred by increased maintenance

The focus of this study was on the optimisation of transfer chutes and

investigations were carried out to determine the core problems These

investigations were done by observing and monitoring various grades of iron ore

passing through transfer chutes known to have throughput problems The core

problems were identified as high wear on liners in the impact zones skew

loading on receiving conveyors material spillage and chute blockages

These problems cause financial losses to the facility either directly or indirectly

Direct financial losses can be attributed to the frequent replacement of chute

liners while the indirect financial losses are caused by facility down time This is

why it is imperative to optimise the manner in which the transfer of material is

approached A new transfer chute configuration addresses the problems

identified at the facility and the core concepts can be adopted at any bulk

materials handling facility

This new concept examines the utilisation of the hood and spoon concept rather

than the conventional dead box configuration By using the hood and spoon

configuration the material discharge velocity is utilised and carried through to the

discharge onto the receiving conveyor Adding to this design is a honeycomb

dead box configuration in the high impact zones of the hood and spoon This

initiates material on material flow and prolongs the lifetime of the chute liners


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CHAPTER 6

The radius of the hood should be designed so that it follows the path of the

material trajectory as closely as possible Some facility constraints prohibit this

hood radius from following exactly the same path as the material The radius of

the spoon is designed in such a manner that it receives the material from the

hood and slows it down while turning it into the direction in which the belt is

running Ideally the material should be discharged from the spoon at

approximately the same velocity as the receiving conveyor

If this can be achieved then some major problems suffered by the industry will

have been resolved With the hood having almost the same radius as the

material trajectory impact wear on liners can be significantly reduced By

discharging material from the chute onto the receiving conveyor at the same

velocity as the conveyor belt excessive belt wear and material spillage will be

avoided Further optimisation is however still possible by investigating the

implementation of various skirting options to the side of the conveyor

This new transfer chute configuration also boasts an articulated bottom section in

the spoon The purpose of the adjustable bottom section is to create greater

clearance below the spoon This will allow material on the belt below to pass

unimpeded underneath the spoon In some cases there can be several chutes in

series that discharge onto the same conveyor In these cases it is beneficial to

incorporate an articulated chute in order to have the capability of having a small

drop height between the discharge point in the chute and the receiving conveyor

This low drop height also minimises turbulent flow at the chute discharge point on


The most unique feature to the new design is the implementation of the

honeycomb dead box configuration in the high impact zones Due to these high

impact areas the liners will experience the most wear This section of the chute

is flanged and can be removed separately from the rest of the chute to aid

maintenance In most maintenance operations it may only be necessary to reline The optimisation of transfer chutes in the bulk materials industry

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this small section of the chute Costs are minimised by reducing the time

required for maintenance and the cost of replacing liners

Previously testing of new transfer chute configurations normally involved

implementing the chute and obseNing its ability to perform according to

specification This can however be a costly exercise as it is possible that further

modifications to the chute will be required after implementation Therefore it is

beneficial to verify the new chute configuration before implementation

This is done by simulating the material flow through the chute using Discrete

Element Method A comparison was done between the actual flow in an eXisting

chute and the simulated flow in the same chute configuration This comparison

showed the same result obtained from the simulation and the actual material

flow This method can therefore be used as an accurate simulation tool for

evaluating transfer chute performance

The mathematical calculations describing the material flow in and over the

honeycomb dead box structures are complex Therefore simulation models are

used to show the material behaviour in those areas Simulations show that the

material captured within the dead boxes remains stationary thus protecting the

ceramic liners behind it This is the desired result as it prolongs the life of the

chute liners and reduces maintenance frequencies

If the work is done efficiently it normally takes two days to remove a worn chute

of this configuration fully and replace it with a new one This is normally done

once a year due to the design lifetime of the chute With the new chute

configuration this maintenance schedule can be reduced to two hours once a

year for the replacement of the honeycomb sections only The exposed face of

the honeycomb ribs will wear through until the efficiency of the honeycomb

design is reduced


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This specific iron ore facility has approximately fifty transfer points During this

exercise only two of these transfer points were replaced with the new chute

configuration The combined annual maintenance time for replacement of these

50 chutes is 100 days If the new chute philosophy is adopted on all these

transfers the annual maintenance time can be reduced to as little as 100 hours

This excludes the unplanned work for cleaning of spillages and fixing or replacing

worn conveyors

There are significant benefits to investigating the problems at specific transfer

points before attempting a new design This gives good insight into where the

focus should be during the design process Ea~y identification and

understanding of the problem areas is essential for a new chute configuration

The new design features can provide a vast improvement and a large benefit to

the bulk materials handling industry

62 RECOMMENDATIONS FOR FURTHER STUDY

During the chute performance tests it was noted that avalanches on the

stockpiles during reclaiming of material causes peaks on the conveyor systems

These peaks in the material stream increase the probability of blockages in the

transfer chutes As a result material spillage occurs and the conveyor belts can

be easily overloaded

This occurrence creates the requirement for further studies on the reclaiming

operations All stacker reclaimers are operated manually which creates ample

room for error Investigations can be done to determine the value of automating

the reclaiming operations Manual interaction cannot be avoided but an

automated system will reduce the possibility for error

Visual inspections on the transfer chute liners indicate that the material tends to

erode the liners away quicker in the grooves between liner plates or ceramic


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tiles This occurrence seems to be worse in areas of the chute where the

material velocity is the highest

This problem was specifically noticed with ceramic liner tiles The tiles are glued

to the chute surface with an epoxy and this substance also fills the crevices

between the tiles This epoxy is however not resistant to any type of sliding or

impact abrasion If the material gains speed in such a groove between the tiles it

simply erodes the epoxy away Studies to reduce or even eliminate this problem

should be examined

In some situations the layout and configuration of the chute prohibits the tiles

from being inserted in a staggered manner Studies can be done on the

composition of this epoxy in order to increase its resistance to sliding and impact

abrasion By doing so the lifetime of the chute liners can be increased which will

result in minimised facility down time due to maintenance

It seems that it is a global industry problem to find accurate scientific methods of

determining material input parameters for OEM simulations Although most of

the material properties can be determined through testing it is still a challenge to

convert that information into a representative input parameter into OEM It is

therefore recommended that further studies be undertaken to determine a

method by which material test data can be successfully converted into OEM input

parameters


MN van Aarde

104

REFERENCES ------shy

REFERENCES

[1] ARNOLD P C MCLEAN A G ROBERTS A W 1978 Bulk Solids

storage flow and handling Tunra Bulk Solids Australia Jan

[2] ANON 2008 Peak (Export) OilUSD Survival Dec

httppeakoHsurvivalorgltag=finance Date of access 8 Jun 2009

[3] KESSLER F 2006 Recent developments in the field of bulk conveying

FME Transactions Vol 34 NO4

[4] ANON 2007 Specification for Troughed Belt Conveyors British

Standards BS28901989 25 Sep Date of access 8 Jun 2009

[5] CEMA (Conveyor Equipment Manufacturers Association) Belt Conveyors

6thfor Bulk Materials ed wwwcemanetorg Date of access

10 Jun 2009

[6] DEWICKI G 2003 Computer Simulation of Granular Material Flows

Overland Conveyor Co Inc Jan httpwwwpowderandbulkcom Date

of access 10 Jun 2009

[7] AMERICAN COAL COUNCIL 2009 Engineered chutes control dust for

Ameren U Es Meramec Plant httpwww clean-coal infold rupalindexphp

Date of access 12 Jun 2009

[8] KUMBA IRON ORE 2008 Annual Financial Statements 2008

httpwwwsishenironorecompanycozareportskumba afs 08pdffullpdf



MN van Aarde

105

REFERENCES

[9] METSO BACKGROUNDER 2007 Rock Crushing 22 Feb

httpWWvVmetsocom Date of access 15 Jun 2009

[10] ALTHOFF H 1977 Reclaiming and Stacking System Patent US

4037735

[11] THE SOUTH AFRICAN INSTITUTE OF MATERIALS HANDLING

Conveyor belt installations and related components Chutes Level 1

course on belt conveying technology

httpWWvVsaimhcozaeducationcourse01chuteshtm Date of access

18 Jun 2009

[12] CLARKE R 2008 Hood and spoon internal flow belt conveyor transfer

systems SACEA - seminar 22 Aug httpWWvVsaceaorgzaDate of

access 22 Jun 2009

[13] T W WOODS CONSTRUCTION 2009 Design problems in coal transfer

chutes 24 Mar httpWWvVferretcomaucTW-Woods-Constructions


[14] LOUGHRAN J 2009 The flow of coal through transfer chutes 20 Aug

Showcase of research excellence James Cook University Australia

[15] ONEIL M 2006 A guide to coal chute replacement Power Engineering

International Nov httpgoliathecnextcomcoms2lgi 0198-369643Ashy

guide-to-coal-chutehtml Date of access 3 Jul 2009

[16] NORDELL LK 1992 A new era in overland conveyor belt design

httpWWvVckitcozasecureconveyorpaperstroughedoverlandoverland

htm Date of access 3 Jul 2009


MN van Aarde

106

REFERENCES

[17] Rowland C 1992 Dust Control at Transfer Points

httpwwwckitcozasecureconveyorpapersbionic-research-2d-bri2shy

paper05htm Date of access 4 Jul 2009

[18] KRAM ENGINEERING Ceramic composite impact blocks

httpwwwkramengineeringcozacercomhtmIDate of access

5 Jul 2009

I19] BLAZEK C 2005 Kinkaid InteliFlo tradeInstallation Source for Plats

Power Atticle Oct

httpwwwbenetechusacompdf caseStudyBe neKi ncArti c pdf

Date of access 10 Aug 2009

[20] CRP Engineering Corp Modern Transfer Chute Designs for Use in

Material Handling

httpwwwcbpengineeringcompdflTransfer Chutespdf Date of access

26 Apr 2010

[21] ROZENTALS J 2008 Rational design of conveyor chutes Bionic

Research Institute South African Institute of Materials Handling

[22] ROBERTS AW SCOTT OJ 1981 Flow of bulk solids through

transfer chutes of variable geometry and profile Bulk Solids Handling

1(4) Dec

[23] CARSON JW ROYAL TA GOODWILL DJ 1986 Understanding

and Eliminating Particle Segregation Problems Bulk Solids Handling

6(1) Feb

[24] BENJAMIN CW 2004 The use of parametric modelling to design

transfer chutes and other key components Gulf Conveyor Group The optimisation of transfer chutes in the bulk materials industry

MN van Aarde

107

l25] STUART DICK D ROYAL TA 1992 Design Principles for Chutes to

Handle Bulk Solids Bulk Solids Handling 12(3) Sep

[26J REICKS AV RUDOLPHI TJ 2004 The Importance and Prediction of

Tension Distribution around the Conveyor Belt Path Bulk materials

handling by conveyor belt 5(2)

(271 RAMOS CM 1991 The real cost of degradation

institute Chute design conference 1991

Bionic research

[28] ROBERTS AW 1969 An investigation of the gravity flow of non

cohesive granular materials through discharge chutes Transactions of

the ACMEjournal of engineering for indust~ May

[29] TAYLOR HJ 1989 Guide to the design of transfer chutes and chute

linings for bulk materials

association 1989

mechanical handling engineers

[30] ROBERTS AW 1999 Chute design application transfer chute design

Design guide for chutes in bulk solids handling The University of

Newcastle Australia

[31] NORDELL LK 1994 Palabora installs Curved Transfer Chute in Hard

Rock to Minimise Belt Cover Wear Bulk Solids Handling 14 Dec

[32] ROZENTALS J 1991 Flow of Bulk Solids in Chute Design

research institute Chute design conference 1991

Bionic


MN van Aarde

108

REFERENCES

[33] ROBERTS AW WICHE SJ 2007 Feed Chute Geometry for

Minimum Belt Wear (h International conference of bulk materials

handling 17 Oct

[34J POWDER HANDLING New OEM Conveyor Transfer Chute Design

Software Helix Technologies

httpvwvwpowderhandlingcomauarticesnew-dem-conveyor-transfershy

chute-design-software Date of access 12 Aug 2009

[35J SAWLEY ML CLEARY PW 1999 A Parallel Discrete Element

Method for Industrial Granular Flow SimUlations EPFL - Super

Computing Review (11)

[36] DEWICKI G 2003 Bulk Material Handling and Processing - Numerical

Techniques and Simulation of Granular Material Overland Conveyor

Company Bulk Solids Handling 23(2)

[37J FA VIER J 2009 Continuing Improvements Boost use of Discrete

Element Method Oil and Gas Engineer- Production Processing 7 Oct

[38] KRAUS E F KA TTERFELD A Usage of the Discrete Element Method in

Conveyor Technologies Institute for Conveyor Technologies (IFSL) The

Otto-von-Guericke University of Magdeburg

[39] MOYS MH VAN NIEROP MA VAN TONDER JC GLOVER G

2005 Validation of the Discrete Element Method (OEM) by Comparing

Predicted Load Behaviour of a Grinding Mill with Measured Data School

for Process and Materials Engineering University of Witwatersrand

Johannesburg The optimisation of transfer materials industry

MN van Aarde

109

REFERENCES

[40J MciLVINA P MOSSAD R 2003 Two dimensional transfer chute

analysis using a continuum method Third international conference on

CFD in the Minerals and Process Industry CSIRO Melbourne Australia

(41J Overland Conveyor Company Inc 2009 Applied DEM

httpwwwapplieddemcomDate of access 26 Apr 2010

(42] DEM SOLUTIONS 2008 Advanced Particle Simulation Capabilities with

EDEM 21 Press release 5 Nov

[43J DEM SOLUTIONS 2008 Martin Engineering Expands use of EDEMTM

Software in Design of Solids Handling Equipment Press release 20 Feb

(44] COETZEE CJ ELS DNJ 2009 Calibration of Discrete Element

Parameters and the Modelling of Silo Discharge and Bucket Filling

Computers and Electronics in Agriculture 65 Mar

[45] DAVID J KRUSES PE Conveyor Belt Transfer Chute Modelling and

Other Applications using The Discrete Element Method in the Material

Handling Industry

httpwwwckitcozasecureconveyorpaperstrouqhedconveyorconveyor

Date of access 3 Sep 2009

bulk materials industry

MN van Aarde

110

ApPENDIXA

ApPENDIX A MATERIAL TESTS AND LINER SELECTiON

The optimisation of-transfer chutes in the bulk materials industry

MN van Aarde

11-1

ApPENDIX A

MATERIAL TEST WORK AND LINER SELECTION

Material samples were taken from the stockpile area for evaluation and testing

These samples represent the worst case materials for impact wear and flow

problems Tests were conducted by external consultants as this is a speciality

field Therefore no detail information on how the tests are conducted is currently

available Results from these tests should indicate the worst case parameters for

chute design according to each specific liner type tested

The material handled by the facility varied from 4 mm to 34 mm lump size A mid

range lump size ore was identified as the preferred material to use for wear

testing This decision was based on the specific ore type maximum lump size of

15 mm as required for the wear test The wear test apparatus used cannot

provide conclusive results with the larger lump sizes of 34 mm and thus smaller

sizes are used Guidance on which ore samples to take was given by the

external consultants tasked with performing the test work

The test work is divided into two sections Firstly the flow test work is carried out

on the finer material with a higher clay content known to have bad flow angles

Included in the selection of fine materials is a sample of the scraper dribblings

This is the material scraped off the belt underneath the head pulley Secondly

the wear tests were conducted on 15 mm samples as explained above

A few common liners were selected for testing These liners are shown in

Table A Some of these liners are known for their specific purpose and

characteristics Polyurethane is known to have a very good coefficient of friction

and will therefore improve the flow of material This material does however

wear out quicker in high impact applications Therefore it is only considered for

use inside the dribbling chute


MN van Aarde

112

ApPENDIX A

As can be seen from Figure 37 in section 432 the dribbling chute will only see

scraper dribblings from the primary and secondary scrapers It is protected from

any main stream flow of material by the start up chute This makes the

polyurethane liner a prime candidate for lining this section of the chute

Table A Material tested vs liner type

I Flow Tests Wear Tests

Liner T

en aJ c

u

I

i

N en aJ c

u

Cf)

en aJ c

u

I en

shy OJaJ C 0 shyj -shy 0 u pound

(f) shy0

T

aJ ~ j 0 0

N aJ ~ j 0 0 i

I Chrome x x x x x

Carbide

x x x x xI VRN 500 I

x x x x x x94

Alumina

Ceramic i I

Poly x

Urethane I I I

FLOW TEST WORK

The fines 1 sample was tested at three different moisture contents of 36 41

and 47 This is 70 80 and 90 of saturation moisture respectively No

noticeable difference was observed in the wall friction angles Therefore the

fines 2 and fines 3 samples were tested at 80 of saturation which is 42 and

43 moisture content respectively

Test work showed that the minimum chute angle required for flow increased as

the impact pressure increased Chute angles were measured up to impact

pressures of about 8 kPa The worst chute angle obtained was 62deg This means

that no angle inside the chute should be less than 62deg from the horizontal

The industry 113

MN van Aarde

ApPENDIXA

The scraper dribblings were tested at a moisture content of 12 This material

possesses the most clay content and therefore has the worst flow properties

During testing of this material water was added to improve the flow At an

impact pressure of 03 kPa the minimum chute angle drops from 62deg to 56deg when

adding a fine mist spray of water

WEAR TEST WORK

As stated in chapter 4 wear tests were conducted on the chrome carbide

overlay ceramics and VRN500 The results of these tests are shown as non

dimensional wear ratios of mm wearmm travel of bulk solid sliding on the wear

liners coupon at a given force Test results shown in Table B indicate that the

chrome carbide will have about 185 times the lifetime of 94 alumina ceramics

The VRN500 liner will wear about 6 times faster than the 94 alumina ceramics

at the same force

Table B Wear ratios of liners at two different pressure ranges

lore Wall Coupon 65 kPa 163kPa -173 kPa I i

Coarse 1 on 94 Alumina Ceramic 90 E-9 37 E-8

Coarse 1 on Chrome Carbide 87 E-9 20 E-8

Coarse 1 on VRN500 91 E-8 I 24 E-7 i

Coarse 2 on 94 Alumina Ceramics 38 E-9 22 E-8


Coarse 2 on VRN500 66 E-8 25 E-7 I

LINER SELECTION

The lifetime of the liners is not the only criteria Maintainability and cost are also

factors that must be considered Chrome carbide seems to be the liner of choice

for this application However the specific type of chrome carbide tested is not

The optimisation of transfer chutes industry 114

MN van Aarde

ApPEND[xA

manufactured locally and the imported cost is approximately three times that of

ceramics

VRN500 is slightly cheaper than ceramics and can easily be bolted to the back

plate of the chute which makes maintenance very simple Ceramics are

however widely used on the facility and the maintenance teams are well trained

for this specific liner Therefore 94 alumina ceramics is chosen for this

application


MN van Aarde

115

ApPENODlt B

ApPENDIX B CHUTE CONTROL PHILOSOPHY

The optfmisation of transfer chutes in the bulk materials industry

MN van Aarde

116

ApPENDIX B

SPOON IN THE OPERATING POSITION

For the spoon to be in the operating position the moving head must be over that

specific spoon and the feeding stockyard conveyor must be running This means

that material will be fed through the chute In this case the spoon needs to be in

the operating position to prevent spillage

However when the chute is in the operating position and the feeding conveyor

trips for any reason the actuated spoon section must not move to the non

operating position If the spoon position feedback fails then the system must trip

and the spoon must remain in its last position The downstream conveyor must

also fail to start with this condition

SPOON IN THE NON OPERATING POSITION

As a rule the spoon needs to be in the non operating position when the moving

head on that specific stockyard conveyor is in the purging position (position C)

The reason is that when a stacker reclaimer is in stacking mode any upstream

stacker reclaimer can be reclaiming The reclaimed material on CV 5 or CV 6

will have to pass underneath the actuated chute

ACTUATED SPOON OVER CV 5

As an example for the movement of any actuated spoon on CV 5 the following

are considered When the moving heads of any of the stockyard conveyors are

in position A and that specific stockyard conveyor is running then the rest of the

actuated spoons over CV 5 must be in the non operating position The

following scenario provides a better understanding

bull CV 4 is running

bull CV 4 moving head is in position A


MN van Aarde

117

ApPENDIXB

In this situation all the actuated spoons on CV 5 except underneath CV 4

must be in the non operating position




in position B and that specific stockyard conveyor is running then the rest of the


following scenario is similar to 453 but explains the control philosophy for the

moving head in position B


bull CV 2 moving head is in position B



The optimisation of transfer chutes in bulk materials industry

MN van Aarde

118

ABSTRACT

ABSTRACT

Bulk materials handling is a rapidly growing global industry Immense challenges

exist to improve the efficiency and cost effectiveness of transporting and handling

bulk materials continuously The nature and scale of bulk materials handling

varies from country to country This study specifically focuses on the handling of

bulk materials in the mining sector

Within this industry transfer chutes are a key component used for transferring

bulk material from one conveyor to another Among other uses it can also be

used under hoppers or silos to transfer material to conveyors trains trucks or

ships In a continuous effort to improve the efficiency of processes the industry is

bombarded with transfer chute problems that include

bull blocked chutes

bull high wear of liner materials

bull spillage due to skew loading

bull conveyor belt wear at loading points

Thorough investigation of existing transfer points before modifying or replacing

them with another configuration gives better insight into the problems This aids

the designer to come up with the optimum solution for a speciAc transfer point In

this dissertation a study is done on the configuration of dynamic chutes or hood

and spoon chutes After completing a detailed investigation of existing problems

the study focuses on rectifying material transfer problems and designing for ease

of maintenance

Adding to the improved flow in the new design for the specific case study

discussed in this dissertation other design details are discussed which further

validates the new design This design improves the wear life of the liners inside

the chute and minimises down time by reducing maintenance shutdowns


MN van Aarde

ii

ABSTRACT











study


MN van Aarde

iii

SAMEVATTING

SAM EVATTING

















vervoerbande











MN van Aarde

iv

SAMEVATTING
















industrie


MN van Aarde

v

ACKNOWLEDGEMENTS

ACKNOWLEDGEMENTS


degree







MN van Aarde

vi


TABLE OF CONTENTS

Abstract ii

Samevatting iv

Acknowledgements vi


List of figures ix

List of tables xii

Nomenclature xiii








21 Preface 22





26 Conclusion37


31 Preface 40





36 Conclusion55


MN van Aarde

vii

TABLE OF CONTENTS


41 Preface 58





46 Conclusion75


51 Preface 78





location 92


58 Conclusion 97




References 1 05




MN van Aarde

viii

LIST OF FIGURES

LIST OF FIGURES
























[32] 35






MN van Aarde

ix

LIST OF FIGURES






















feeders [36J 80











MN van Aarde

x

OF FIGURES




MN van Aarde

xi

LIST OF TABLES

LIST OF TABLES





M N van Aarde

xii

---------------------------------

CV

NOMENCLATURE

NOMENCLATURE

SCADA

CCTV

CEMA

DEM

kPa

mm

MSHA

ms

mt

MW

NIOSH

OSHA

RampD

tlh

3D




Conveyor


Kilopascal

Millimetres


Metres per second

Metric Tons

Megawatt



Radius of curvature


Tons per hour

Three Dimensional


MN van Aarde

xiii

CHAPTER 1




MN van Aarde

1

CHAPTER 1













significant

o



MN van Aarde

2

CHAPTER 1



























MN van Aarde

3

CHAPTER 1 - ----~--~--------------~--------




Figure 3








MN van Aarde

4

CHAPTER 1











the most extreme




Sishen entails [8]










11 N van Aarde

5

CHAPTER 1

121 Crushing














requirements



MN van Aarde

6

CHAPTER 1
















MN van Aarde

7

CHAPTER 1











conveyor [10]









used








MN van Aarde

8

CHAPTER 1














MN van Aarde

9

CHAPTER 1










MN van Aarde

10

CHAPTER 1








COVERED










MN van Aarde

11

CHAPTER 1






bull Spillage

bull Blocked chutes







transfer chute






MN van Aarde

CHAPTER 1











MN van Aarde

13

CHAPTER 1 --~ ---------------------------shy





dust emissions

















shown in Figure 14


MN van Aarde

14

CHAPTER 1














MN van Aarde

15

CHAPTER 1










MN van Aarde

16

CHAPTER 1













eliminated [13]




MN van Aarde

17

CHAPTER 1



design























MN van Aarde

CHAPTER 1





performance



















new transfer chutes




MN van Aarde

CHAPTER 1







chapter











facility


MN van Aarde

20

CHAPTER 2



MN van Aarde

21

CHAPTER 2

21 PREFACE





















solution





MN van Aarde

22

CHAPTER 2


catered for


the conveyor




the belt










MN van Aarde

23

CHAPTER 2


Aria Unit

Feed Conveyor

Belt Speed r ms

Belt Width mm


Pulley Width mm



Sight Height Data


Drop Height mm


Receiving Conveyor

Belt Speed ms

Belt Width mm

Belt Thickness mm




Material Properties








Inc are [25]


MN van Aarde

24

CHAPTER 2



























MN van Aarde

25

CHAPTER 2














clean [25]










M N van Aarde

26

CHAPTER 2








possible [25]


CONSTRAINTS




handled [1]





I I




L J -





MN van Aarde

27

CHAPTER 2



















MN van Aarde

28

CHAPTER 2















start up



MN van Aarde

29

CHAPTER 2













x

Vo

- ImpactPlate



MN van Aarde

30

CHAPTER 2





















MN van Aarde

31

CHAPTER 2 ---~----------------






reduced [29]


(1)






v = material speed










MN van Aarde

CHAPTER 2

[1 + ( gx )]15 R = vcos8

c (2)

vcos8

Where


v == material speed




















MN van Aarde

33

CHAPTER 2




























MN van Aarde

34

CHAPTER 2


_ IIU _ Im _ I rn _ 171-111 _ u n _ ~ l

_ 4 ~

_ 41 _ 4


~ 1m bull UI2








MN van Aarde

35

CHAPTER 2











is determined and

(4)


MN van Aarde

36

CHAPTER 2

Mass Flow Rate Omh










26 CONCLUSION






MN van Aarde

37

CHAPTER 2










facility limits







MN van Aarde

38

CHAPTER 3


MN van Aarde



39

CHAPTER 3

31 PREFACE




















chute

32 TEST METHODOLOGY






MN van Aarde

40

CHAPTER 3





















sidewalls






MN van Aarde

CHAPTER 3


fUnction







problems





conveyor













MN van Aarde

42

CHAPTER 3









CV4 CV3 CV2 CV1







MN van Aarde

43

CHAPTER 3





90 de-g TRANSFBt











MN van Aarde

44

CHAPTER 3


4 mm and 12 mm



Fine K 5mm

Fine N 8mm

Fine A 8mm

Coarse K 25mm

Coarse D 34mm

Coarse S 12 mm

Coarse A 20mm










MN van Aarde

45

CHAPTER 3












MN van Aarde

46

CHAPTER 3












MN van Aarde

47

CHAPTER 3



























MN van Aarde

48

CHAPTER 3



343 Spillag3















cable


MN van Aarde

49

CHAPTER 3









before loading



MN van Aarde

50

CHAPTER 3

















conveyor system










MN van Aarde

51

CHAPTER 3


constant rate







IlmJ



C)


t) cent


~~ Ii ~ ~ g i i ~ 4 1 J yen i


Time







MN van Aarde

52

CHAPTER 3
















MN van Aarde

53

CHAPTER 3




CV11 CV5 Yes






CV31 CV5 Yes

Yes

Yes





No (Mech trip on




No (Feed to CV 2






MN van Aarde

54

CHAPTER 3





than 10000 tlh






10000 tlh







36 CONCLUSION










MN van Aarde

55

CHAPTER 3




















transfer chutes


MN van Aarde

56

CHAPTER 4


RECURRING PROBLEMS


MN van Aarde

57

CHAPTER 4

41 PREFACE




















feeding conveyor






MN van Aarde

58

CHAPTER 4















t4CLIE SECTION

PURGING POSmON







MN van Aarde

59

CHAPTER 4












I ~

j







MN van Aarde

60

CHAPTER 4
















chute








MN van Aarde

61

CHAPTER 4 -__-----__---_----------shy


















MN van Aarde

62

CHAPTER 4

START-UP CHrrlE

DRlBBIlNG CHUTE
















MN van Aarde

63

CHAPTER 4 -__----- ------shy





















hood surface







MN van Aarde

64

-----

CHAPTER 4


70

--- --~ 6 0

5 0

40 ~_

~ 30 g --- a 20 gt

10

00


















MN van Aarde

65

CHAPTER 4


67

66

65

S 64 amp0 g 6 3

V

v-shy ~ ~

ii ~ gt 62

61 I I 60

o 10 20 30 40 50 60



















MN van Aarde

66

CHAPTER 4


chute














M N van Aarde

67

CHAPTER 4




















e = tan- I ( 1 ) (5)

C Ii







MN van Aarde

CHAPTER 4













MN van Aarde

69

CHAPTER 4

WEAR BOX








inside


MN van Aarde

70

CHAPTER 4 ----_----------------shy




















MN van Aarde

71

CHAPTER 4 ------------_ -- - ---------------shy






section as shown in











MN van Aarde

72

CHAPTER 4
















MN van Aarde

73

CHAPTER 4












MN van Aarde

74

CHAPTER 4










46 CONCLUSION








MN van Aarde

75

CHAPTER 4



















MN van Aarde

76

CHAPTER 5




MN van Aarde

CHAPTER 5

51 PREFACE





















MN van Aarde

78

CHAPTER 5












expensive [34]









chute designs







MN van Aarde

79

CHAPTER 5










collision








time [37]


MN van Aarde

80

CHAPTER 5





equipmentshy




segregation


process


of the simulation














MN van Aarde

81

CHAPTERS













of the design










this dissertation


MN van Aarde

82

CHAPTER 5












MN van Aarde

83

CHAPTER 5




























MN van Aarde

84

CHAPTER 5


software of choice





must be rendered


manufacturing







9 Manufacture

10 Installation











M N van Aarde

85

CHAPTER 5




























MN van Aarde

86

CHAPTER 5




























MN van Aarde

87

CHAPTER 5








APPLICATION





correctly





MN van Aarde

CHAPTER 5


ore type
















MN van Aarde

89

CHAPTER 5


by Figure 52








Off-centre loading

L



MN van Aarde

90

CHAPTER 5


Low velocity layer









transfer point










MN van Aarde

91

CHAPTER 5






HOOD LOCATION









I

L



MN van Aarde

92

CHAPTER 5














MN van Aarde

93

CHAPTER 5


Slower material

L














MN van Aarde

94

CHAPTERS ----------------- -------___ _--shy














chute










MN van Aarde

95

CHAPTER 5

Large radius hood



belt

L


Spoon





MN van Aarde

96

CHAPTERS













however minimised

58 CONCLUSION







with OEM







MN van Aarde

97

CHAPTER 5













MN van Aarde

98

CHAPTER 6



MN van Aarde

99

CHAPTER 6




























MN van Aarde

100

CHAPTER 6





























MN van Aarde

101

CHAPTER 6


























design is reduced


MN van Aarde

102

CHAPTER 6







worn conveyors





















MN van Aarde

103

CHAPTER 6








should be examined












parameters


MN van Aarde

104


REFERENCES











10 Jun 2009











MN van Aarde

105

REFERENCES




4037735





18 Jun 2009



access 22 Jun 2009













MN van Aarde

106

REFERENCES






5 Jul 2009


Power Atticle Oct




Material Handling


26 Apr 2010





1(4) Dec



6(1) Feb



MN van Aarde

107








Bionic research






association 1989




Newcastle Australia





Bionic


MN van Aarde

108

REFERENCES



handling 17 Oct





















MN van Aarde

109

REFERENCES















Handling Industry




MN van Aarde

110

ApPENDIXA



MN van Aarde

11-1

ApPENDIX A



























MN van Aarde

112

ApPENDIX A







Liner T

en aJ c

u

I

i

N en aJ c

u

Cf)

en aJ c

u

I en


(f) shy0

T

aJ ~ j 0 0

N aJ ~ j 0 0 i

I Chrome x x x x x

Carbide


x x x x x x94

Alumina

Ceramic i I

Poly x

Urethane I I I

FLOW TEST WORK










The industry 113

MN van Aarde

ApPENDIXA






WEAR TEST WORK







at the same force









LINER SELECTION





MN van Aarde

ApPEND[xA


ceramics





application


MN van Aarde

115

ApPENODlt B



MN van Aarde

116

ApPENDIX B


























MN van Aarde

117

ApPENDIXB















MN van Aarde

118

ABSTRACT











study


MN van Aarde

iii

SAMEVATTING

SAM EVATTING

















vervoerbande











MN van Aarde

iv

SAMEVATTING
















industrie


MN van Aarde

v

ACKNOWLEDGEMENTS

ACKNOWLEDGEMENTS


degree







MN van Aarde

vi


TABLE OF CONTENTS

Abstract ii

Samevatting iv

Acknowledgements vi


List of figures ix

List of tables xii

Nomenclature xiii








21 Preface 22





26 Conclusion37


31 Preface 40





36 Conclusion55


MN van Aarde

vii

TABLE OF CONTENTS


41 Preface 58





46 Conclusion75


51 Preface 78





location 92


58 Conclusion 97




References 1 05




MN van Aarde

viii

LIST OF FIGURES

LIST OF FIGURES
























[32] 35






MN van Aarde

ix

LIST OF FIGURES






















feeders [36J 80











MN van Aarde

x

OF FIGURES




MN van Aarde

xi

LIST OF TABLES

LIST OF TABLES





M N van Aarde

xii

---------------------------------

CV

NOMENCLATURE

NOMENCLATURE

SCADA

CCTV

CEMA

DEM

kPa

mm

MSHA

ms

mt

MW

NIOSH

OSHA

RampD

tlh

3D




Conveyor


Kilopascal

Millimetres


Metres per second

Metric Tons

Megawatt



Radius of curvature


Tons per hour

Three Dimensional


MN van Aarde

xiii

CHAPTER 1




MN van Aarde

1

CHAPTER 1













significant

o



MN van Aarde

2

CHAPTER 1



























MN van Aarde

3

CHAPTER 1 - ----~--~--------------~--------




Figure 3








MN van Aarde

4

CHAPTER 1











the most extreme




Sishen entails [8]










11 N van Aarde

5

CHAPTER 1

121 Crushing














requirements



MN van Aarde

6

CHAPTER 1
















MN van Aarde

7

CHAPTER 1











conveyor [10]









used








MN van Aarde

8

CHAPTER 1














MN van Aarde

9

CHAPTER 1










MN van Aarde

10

CHAPTER 1








COVERED










MN van Aarde

11

CHAPTER 1






bull Spillage

bull Blocked chutes







transfer chute






MN van Aarde

CHAPTER 1











MN van Aarde

13

CHAPTER 1 --~ ---------------------------shy





dust emissions

















shown in Figure 14


MN van Aarde

14

CHAPTER 1














MN van Aarde

15

CHAPTER 1










MN van Aarde

16

CHAPTER 1













eliminated [13]




MN van Aarde

17

CHAPTER 1



design























MN van Aarde

CHAPTER 1





performance



















new transfer chutes




MN van Aarde

CHAPTER 1







chapter











facility


MN van Aarde

20

CHAPTER 2



MN van Aarde

21

CHAPTER 2

21 PREFACE





















solution





MN van Aarde

22

CHAPTER 2


catered for


the conveyor




the belt










MN van Aarde

23

CHAPTER 2


Aria Unit

Feed Conveyor

Belt Speed r ms

Belt Width mm


Pulley Width mm



Sight Height Data


Drop Height mm


Receiving Conveyor

Belt Speed ms

Belt Width mm

Belt Thickness mm




Material Properties








Inc are [25]


MN van Aarde

24

CHAPTER 2



























MN van Aarde

25

CHAPTER 2














clean [25]










M N van Aarde

26

CHAPTER 2








possible [25]


CONSTRAINTS




handled [1]





I I




L J -





MN van Aarde

27

CHAPTER 2



















MN van Aarde

28

CHAPTER 2















start up



MN van Aarde

29

CHAPTER 2













x

Vo

- ImpactPlate



MN van Aarde

30

CHAPTER 2





















MN van Aarde

31

CHAPTER 2 ---~----------------






reduced [29]


(1)






v = material speed










MN van Aarde

CHAPTER 2

[1 + ( gx )]15 R = vcos8

c (2)

vcos8

Where


v == material speed




















MN van Aarde

33

CHAPTER 2




























MN van Aarde

34

CHAPTER 2


_ IIU _ Im _ I rn _ 171-111 _ u n _ ~ l

_ 4 ~

_ 41 _ 4


~ 1m bull UI2








MN van Aarde

35

CHAPTER 2











is determined and

(4)


MN van Aarde

36

CHAPTER 2

Mass Flow Rate Omh










26 CONCLUSION






MN van Aarde

37

CHAPTER 2










facility limits







MN van Aarde

38

CHAPTER 3


MN van Aarde



39

CHAPTER 3

31 PREFACE




















chute

32 TEST METHODOLOGY






MN van Aarde

40

CHAPTER 3





















sidewalls






MN van Aarde

CHAPTER 3


fUnction







problems





conveyor













MN van Aarde

42

CHAPTER 3









CV4 CV3 CV2 CV1







MN van Aarde

43

CHAPTER 3





90 de-g TRANSFBt











MN van Aarde

44

CHAPTER 3


4 mm and 12 mm



Fine K 5mm

Fine N 8mm

Fine A 8mm

Coarse K 25mm

Coarse D 34mm

Coarse S 12 mm

Coarse A 20mm










MN van Aarde

45

CHAPTER 3












MN van Aarde

46

CHAPTER 3












MN van Aarde

47

CHAPTER 3



























MN van Aarde

48

CHAPTER 3



343 Spillag3















cable


MN van Aarde

49

CHAPTER 3









before loading



MN van Aarde

50

CHAPTER 3

















conveyor system










MN van Aarde

51

CHAPTER 3


constant rate







IlmJ



C)


t) cent


~~ Ii ~ ~ g i i ~ 4 1 J yen i


Time







MN van Aarde

52

CHAPTER 3
















MN van Aarde

53

CHAPTER 3




CV11 CV5 Yes






CV31 CV5 Yes

Yes

Yes





No (Mech trip on




No (Feed to CV 2






MN van Aarde

54

CHAPTER 3





than 10000 tlh






10000 tlh







36 CONCLUSION










MN van Aarde

55

CHAPTER 3




















transfer chutes


MN van Aarde

56

CHAPTER 4


RECURRING PROBLEMS


MN van Aarde

57

CHAPTER 4

41 PREFACE




















feeding conveyor






MN van Aarde

58

CHAPTER 4















t4CLIE SECTION

PURGING POSmON







MN van Aarde

59

CHAPTER 4












I ~

j







MN van Aarde

60

CHAPTER 4
















chute








MN van Aarde

61

CHAPTER 4 -__-----__---_----------shy


















MN van Aarde

62

CHAPTER 4

START-UP CHrrlE

DRlBBIlNG CHUTE
















MN van Aarde

63

CHAPTER 4 -__----- ------shy





















hood surface







MN van Aarde

64

-----

CHAPTER 4


70

--- --~ 6 0

5 0

40 ~_

~ 30 g --- a 20 gt

10

00


















MN van Aarde

65

CHAPTER 4


67

66

65

S 64 amp0 g 6 3

V

v-shy ~ ~

ii ~ gt 62

61 I I 60

o 10 20 30 40 50 60



















MN van Aarde

66

CHAPTER 4


chute














M N van Aarde

67

CHAPTER 4




















e = tan- I ( 1 ) (5)

C Ii







MN van Aarde

CHAPTER 4













MN van Aarde

69

CHAPTER 4

WEAR BOX








inside


MN van Aarde

70

CHAPTER 4 ----_----------------shy




















MN van Aarde

71

CHAPTER 4 ------------_ -- - ---------------shy






section as shown in











MN van Aarde

72

CHAPTER 4
















MN van Aarde

73

CHAPTER 4












MN van Aarde

74

CHAPTER 4










46 CONCLUSION








MN van Aarde

75

CHAPTER 4



















MN van Aarde

76

CHAPTER 5




MN van Aarde

CHAPTER 5

51 PREFACE





















MN van Aarde

78

CHAPTER 5












expensive [34]









chute designs







MN van Aarde

79

CHAPTER 5










collision








time [37]


MN van Aarde

80

CHAPTER 5





equipmentshy




segregation


process


of the simulation














MN van Aarde

81

CHAPTERS













of the design










this dissertation


MN van Aarde

82

CHAPTER 5












MN van Aarde

83

CHAPTER 5




























MN van Aarde

84

CHAPTER 5


software of choice





must be rendered


manufacturing







9 Manufacture

10 Installation











M N van Aarde

85

CHAPTER 5




























MN van Aarde

86

CHAPTER 5




























MN van Aarde

87

CHAPTER 5








APPLICATION





correctly





MN van Aarde

CHAPTER 5


ore type
















MN van Aarde

89

CHAPTER 5


by Figure 52








Off-centre loading

L



MN van Aarde

90

CHAPTER 5


Low velocity layer









transfer point










MN van Aarde

91

CHAPTER 5






HOOD LOCATION









I

L



MN van Aarde

92

CHAPTER 5














MN van Aarde

93

CHAPTER 5


Slower material

L














MN van Aarde

94

CHAPTERS ----------------- -------___ _--shy














chute










MN van Aarde

95

CHAPTER 5

Large radius hood



belt

L


Spoon





MN van Aarde

96

CHAPTERS













however minimised

58 CONCLUSION







with OEM







MN van Aarde

97

CHAPTER 5













MN van Aarde

98

CHAPTER 6



MN van Aarde

99

CHAPTER 6




























MN van Aarde

100

CHAPTER 6





























MN van Aarde

101

CHAPTER 6


























design is reduced


MN van Aarde

102

CHAPTER 6







worn conveyors





















MN van Aarde

103

CHAPTER 6








should be examined












parameters


MN van Aarde

104


REFERENCES











10 Jun 2009











MN van Aarde

105

REFERENCES




4037735





18 Jun 2009



access 22 Jun 2009













MN van Aarde

106

REFERENCES






5 Jul 2009


Power Atticle Oct




Material Handling


26 Apr 2010





1(4) Dec



6(1) Feb



MN van Aarde

107








Bionic research






association 1989




Newcastle Australia





Bionic


MN van Aarde

108

REFERENCES



handling 17 Oct





















MN van Aarde

109

REFERENCES















Handling Industry




MN van Aarde

110

ApPENDIXA



MN van Aarde

11-1

ApPENDIX A



























MN van Aarde

112

ApPENDIX A







Liner T

en aJ c

u

I

i

N en aJ c

u

Cf)

en aJ c

u

I en


(f) shy0

T

aJ ~ j 0 0

N aJ ~ j 0 0 i

I Chrome x x x x x

Carbide


x x x x x x94

Alumina

Ceramic i I

Poly x

Urethane I I I

FLOW TEST WORK










The industry 113

MN van Aarde

ApPENDIXA






WEAR TEST WORK







at the same force









LINER SELECTION





MN van Aarde

ApPEND[xA


ceramics





application


MN van Aarde

115

ApPENODlt B



MN van Aarde

116

ApPENDIX B


























MN van Aarde

117

ApPENDIXB















MN van Aarde

118

SAMEVATTING

SAM EVATTING

















vervoerbande











MN van Aarde

iv

SAMEVATTING
















industrie


MN van Aarde

v

ACKNOWLEDGEMENTS

ACKNOWLEDGEMENTS


degree







MN van Aarde

vi


TABLE OF CONTENTS

Abstract ii

Samevatting iv

Acknowledgements vi


List of figures ix

List of tables xii

Nomenclature xiii








21 Preface 22





26 Conclusion37


31 Preface 40





36 Conclusion55


MN van Aarde

vii

TABLE OF CONTENTS


41 Preface 58





46 Conclusion75


51 Preface 78





location 92


58 Conclusion 97




References 1 05




MN van Aarde

viii

LIST OF FIGURES

LIST OF FIGURES
























[32] 35






MN van Aarde

ix

LIST OF FIGURES






















feeders [36J 80











MN van Aarde

x

OF FIGURES




MN van Aarde

xi

LIST OF TABLES

LIST OF TABLES





M N van Aarde

xii

---------------------------------

CV

NOMENCLATURE

NOMENCLATURE

SCADA

CCTV

CEMA

DEM

kPa

mm

MSHA

ms

mt

MW

NIOSH

OSHA

RampD

tlh

3D




Conveyor


Kilopascal

Millimetres


Metres per second

Metric Tons

Megawatt



Radius of curvature


Tons per hour

Three Dimensional


MN van Aarde

xiii

CHAPTER 1




MN van Aarde

1

CHAPTER 1













significant

o



MN van Aarde

2

CHAPTER 1



























MN van Aarde

3

CHAPTER 1 - ----~--~--------------~--------




Figure 3








MN van Aarde

4

CHAPTER 1











the most extreme




Sishen entails [8]










11 N van Aarde

5

CHAPTER 1

121 Crushing














requirements



MN van Aarde

6

CHAPTER 1
















MN van Aarde

7

CHAPTER 1











conveyor [10]









used








MN van Aarde

8

CHAPTER 1














MN van Aarde

9

CHAPTER 1










MN van Aarde

10

CHAPTER 1








COVERED










MN van Aarde

11

CHAPTER 1






bull Spillage

bull Blocked chutes







transfer chute






MN van Aarde

CHAPTER 1











MN van Aarde

13

CHAPTER 1 --~ ---------------------------shy





dust emissions

















shown in Figure 14


MN van Aarde

14

CHAPTER 1














MN van Aarde

15

CHAPTER 1










MN van Aarde

16

CHAPTER 1













eliminated [13]




MN van Aarde

17

CHAPTER 1



design























MN van Aarde

CHAPTER 1





performance



















new transfer chutes




MN van Aarde

CHAPTER 1







chapter











facility


MN van Aarde

20

CHAPTER 2



MN van Aarde

21

CHAPTER 2

21 PREFACE





















solution





MN van Aarde

22

CHAPTER 2


catered for


the conveyor




the belt










MN van Aarde

23

CHAPTER 2


Aria Unit

Feed Conveyor

Belt Speed r ms

Belt Width mm


Pulley Width mm



Sight Height Data


Drop Height mm


Receiving Conveyor

Belt Speed ms

Belt Width mm

Belt Thickness mm




Material Properties








Inc are [25]


MN van Aarde

24

CHAPTER 2



























MN van Aarde

25

CHAPTER 2














clean [25]










M N van Aarde

26

CHAPTER 2








possible [25]


CONSTRAINTS




handled [1]





I I




L J -





MN van Aarde

27

CHAPTER 2



















MN van Aarde

28

CHAPTER 2















start up



MN van Aarde

29

CHAPTER 2













x

Vo

- ImpactPlate



MN van Aarde

30

CHAPTER 2





















MN van Aarde

31

CHAPTER 2 ---~----------------






reduced [29]


(1)






v = material speed










MN van Aarde

CHAPTER 2

[1 + ( gx )]15 R = vcos8

c (2)

vcos8

Where


v == material speed




















MN van Aarde

33

CHAPTER 2




























MN van Aarde

34

CHAPTER 2


_ IIU _ Im _ I rn _ 171-111 _ u n _ ~ l

_ 4 ~

_ 41 _ 4


~ 1m bull UI2








MN van Aarde

35

CHAPTER 2











is determined and

(4)


MN van Aarde

36

CHAPTER 2

Mass Flow Rate Omh










26 CONCLUSION






MN van Aarde

37

CHAPTER 2










facility limits







MN van Aarde

38

CHAPTER 3


MN van Aarde



39

CHAPTER 3

31 PREFACE




















chute

32 TEST METHODOLOGY






MN van Aarde

40

CHAPTER 3





















sidewalls






MN van Aarde

CHAPTER 3


fUnction







problems





conveyor













MN van Aarde

42

CHAPTER 3









CV4 CV3 CV2 CV1







MN van Aarde

43

CHAPTER 3





90 de-g TRANSFBt











MN van Aarde

44

CHAPTER 3


4 mm and 12 mm



Fine K 5mm

Fine N 8mm

Fine A 8mm

Coarse K 25mm

Coarse D 34mm

Coarse S 12 mm

Coarse A 20mm










MN van Aarde

45

CHAPTER 3












MN van Aarde

46

CHAPTER 3












MN van Aarde

47

CHAPTER 3



























MN van Aarde

48

CHAPTER 3



343 Spillag3















cable


MN van Aarde

49

CHAPTER 3









before loading



MN van Aarde

50

CHAPTER 3

















conveyor system










MN van Aarde

51

CHAPTER 3


constant rate







IlmJ



C)


t) cent


~~ Ii ~ ~ g i i ~ 4 1 J yen i


Time







MN van Aarde

52

CHAPTER 3
















MN van Aarde

53

CHAPTER 3




CV11 CV5 Yes






CV31 CV5 Yes

Yes

Yes





No (Mech trip on




No (Feed to CV 2






MN van Aarde

54

CHAPTER 3





than 10000 tlh






10000 tlh







36 CONCLUSION










MN van Aarde

55

CHAPTER 3




















transfer chutes


MN van Aarde

56

CHAPTER 4


RECURRING PROBLEMS


MN van Aarde

57

CHAPTER 4

41 PREFACE




















feeding conveyor






MN van Aarde

58

CHAPTER 4















t4CLIE SECTION

PURGING POSmON







MN van Aarde

59

CHAPTER 4












I ~

j







MN van Aarde

60

CHAPTER 4
















chute








MN van Aarde

61

CHAPTER 4 -__-----__---_----------shy


















MN van Aarde

62

CHAPTER 4

START-UP CHrrlE

DRlBBIlNG CHUTE
















MN van Aarde

63

CHAPTER 4 -__----- ------shy





















hood surface







MN van Aarde

64

-----

CHAPTER 4


70

--- --~ 6 0

5 0

40 ~_

~ 30 g --- a 20 gt

10

00


















MN van Aarde

65

CHAPTER 4


67

66

65

S 64 amp0 g 6 3

V

v-shy ~ ~

ii ~ gt 62

61 I I 60

o 10 20 30 40 50 60



















MN van Aarde

66

CHAPTER 4


chute














M N van Aarde

67

CHAPTER 4




















e = tan- I ( 1 ) (5)

C Ii







MN van Aarde

CHAPTER 4













MN van Aarde

69

CHAPTER 4

WEAR BOX








inside


MN van Aarde

70

CHAPTER 4 ----_----------------shy




















MN van Aarde

71

CHAPTER 4 ------------_ -- - ---------------shy






section as shown in











MN van Aarde

72

CHAPTER 4
















MN van Aarde

73

CHAPTER 4












MN van Aarde

74

CHAPTER 4










46 CONCLUSION








MN van Aarde

75

CHAPTER 4



















MN van Aarde

76

CHAPTER 5




MN van Aarde

CHAPTER 5

51 PREFACE





















MN van Aarde

78

CHAPTER 5












expensive [34]









chute designs







MN van Aarde

79

CHAPTER 5










collision








time [37]


MN van Aarde

80

CHAPTER 5





equipmentshy




segregation


process


of the simulation














MN van Aarde

81

CHAPTERS













of the design










this dissertation


MN van Aarde

82

CHAPTER 5












MN van Aarde

83

CHAPTER 5




























MN van Aarde

84

CHAPTER 5


software of choice





must be rendered


manufacturing







9 Manufacture

10 Installation











M N van Aarde

85

CHAPTER 5




























MN van Aarde

86

CHAPTER 5




























MN van Aarde

87

CHAPTER 5








APPLICATION





correctly





MN van Aarde

CHAPTER 5


ore type
















MN van Aarde

89

CHAPTER 5


by Figure 52








Off-centre loading

L



MN van Aarde

90

CHAPTER 5


Low velocity layer









transfer point










MN van Aarde

91

CHAPTER 5






HOOD LOCATION









I

L



MN van Aarde

92

CHAPTER 5














MN van Aarde

93

CHAPTER 5


Slower material

L














MN van Aarde

94

CHAPTERS ----------------- -------___ _--shy














chute










MN van Aarde

95

CHAPTER 5

Large radius hood



belt

L


Spoon





MN van Aarde

96

CHAPTERS













however minimised

58 CONCLUSION







with OEM







MN van Aarde

97

CHAPTER 5













MN van Aarde

98

CHAPTER 6



MN van Aarde

99

CHAPTER 6




























MN van Aarde

100

CHAPTER 6





























MN van Aarde

101

CHAPTER 6


























design is reduced


MN van Aarde

102

CHAPTER 6







worn conveyors





















MN van Aarde

103

CHAPTER 6








should be examined












parameters


MN van Aarde

104


REFERENCES











10 Jun 2009











MN van Aarde

105

REFERENCES




4037735





18 Jun 2009



access 22 Jun 2009













MN van Aarde

106

REFERENCES






5 Jul 2009


Power Atticle Oct




Material Handling


26 Apr 2010





1(4) Dec



6(1) Feb



MN van Aarde

107








Bionic research






association 1989




Newcastle Australia





Bionic


MN van Aarde

108

REFERENCES



handling 17 Oct





















MN van Aarde

109

REFERENCES















Handling Industry




MN van Aarde

110

ApPENDIXA



MN van Aarde

11-1

ApPENDIX A



























MN van Aarde

112

ApPENDIX A







Liner T

en aJ c

u

I

i

N en aJ c

u

Cf)

en aJ c

u

I en


(f) shy0

T

aJ ~ j 0 0

N aJ ~ j 0 0 i

I Chrome x x x x x

Carbide


x x x x x x94

Alumina

Ceramic i I

Poly x

Urethane I I I

FLOW TEST WORK










The industry 113

MN van Aarde

ApPENDIXA






WEAR TEST WORK







at the same force









LINER SELECTION





MN van Aarde

ApPEND[xA


ceramics





application


MN van Aarde

115

ApPENODlt B



MN van Aarde

116

ApPENDIX B


























MN van Aarde

117

ApPENDIXB















MN van Aarde

118

SAMEVATTING
















industrie


MN van Aarde

v

ACKNOWLEDGEMENTS

ACKNOWLEDGEMENTS


degree







MN van Aarde

vi


TABLE OF CONTENTS

Abstract ii

Samevatting iv

Acknowledgements vi


List of figures ix

List of tables xii

Nomenclature xiii








21 Preface 22





26 Conclusion37


31 Preface 40





36 Conclusion55


MN van Aarde

vii

TABLE OF CONTENTS


41 Preface 58





46 Conclusion75


51 Preface 78





location 92


58 Conclusion 97




References 1 05




MN van Aarde

viii

LIST OF FIGURES

LIST OF FIGURES
























[32] 35






MN van Aarde

ix

LIST OF FIGURES






















feeders [36J 80











MN van Aarde

x

OF FIGURES




MN van Aarde

xi

LIST OF TABLES

LIST OF TABLES





M N van Aarde

xii

---------------------------------

CV

NOMENCLATURE

NOMENCLATURE

SCADA

CCTV

CEMA

DEM

kPa

mm

MSHA

ms

mt

MW

NIOSH

OSHA

RampD

tlh

3D




Conveyor


Kilopascal

Millimetres


Metres per second

Metric Tons

Megawatt



Radius of curvature


Tons per hour

Three Dimensional


MN van Aarde

xiii

CHAPTER 1




MN van Aarde

1

CHAPTER 1













significant

o



MN van Aarde

2

CHAPTER 1



























MN van Aarde

3

CHAPTER 1 - ----~--~--------------~--------




Figure 3








MN van Aarde

4

CHAPTER 1











the most extreme




Sishen entails [8]










11 N van Aarde

5

CHAPTER 1

121 Crushing














requirements



MN van Aarde

6

CHAPTER 1
















MN van Aarde

7

CHAPTER 1











conveyor [10]









used








MN van Aarde

8

CHAPTER 1














MN van Aarde

9

CHAPTER 1










MN van Aarde

10

CHAPTER 1








COVERED










MN van Aarde

11

CHAPTER 1






bull Spillage

bull Blocked chutes







transfer chute






MN van Aarde

CHAPTER 1











MN van Aarde

13

CHAPTER 1 --~ ---------------------------shy





dust emissions

















shown in Figure 14


MN van Aarde

14

CHAPTER 1














MN van Aarde

15

CHAPTER 1










MN van Aarde

16

CHAPTER 1













eliminated [13]




MN van Aarde

17

CHAPTER 1



design























MN van Aarde

CHAPTER 1





performance



















new transfer chutes




MN van Aarde

CHAPTER 1







chapter











facility


MN van Aarde

20

CHAPTER 2



MN van Aarde

21

CHAPTER 2

21 PREFACE





















solution





MN van Aarde

22

CHAPTER 2


catered for


the conveyor




the belt










MN van Aarde

23

CHAPTER 2


Aria Unit

Feed Conveyor

Belt Speed r ms

Belt Width mm


Pulley Width mm



Sight Height Data


Drop Height mm


Receiving Conveyor

Belt Speed ms

Belt Width mm

Belt Thickness mm




Material Properties








Inc are [25]


MN van Aarde

24

CHAPTER 2



























MN van Aarde

25

CHAPTER 2














clean [25]










M N van Aarde

26

CHAPTER 2








possible [25]


CONSTRAINTS




handled [1]





I I




L J -





MN van Aarde

27

CHAPTER 2



















MN van Aarde

28

CHAPTER 2















start up



MN van Aarde

29

CHAPTER 2













x

Vo

- ImpactPlate



MN van Aarde

30

CHAPTER 2





















MN van Aarde

31

CHAPTER 2 ---~----------------






reduced [29]


(1)






v = material speed










MN van Aarde

CHAPTER 2

[1 + ( gx )]15 R = vcos8

c (2)

vcos8

Where


v == material speed




















MN van Aarde

33

CHAPTER 2




























MN van Aarde

34

CHAPTER 2


_ IIU _ Im _ I rn _ 171-111 _ u n _ ~ l

_ 4 ~

_ 41 _ 4


~ 1m bull UI2








MN van Aarde

35

CHAPTER 2











is determined and

(4)


MN van Aarde

36

CHAPTER 2

Mass Flow Rate Omh










26 CONCLUSION






MN van Aarde

37

CHAPTER 2










facility limits







MN van Aarde

38

CHAPTER 3


MN van Aarde



39

CHAPTER 3

31 PREFACE




















chute

32 TEST METHODOLOGY






MN van Aarde

40

CHAPTER 3





















sidewalls






MN van Aarde

CHAPTER 3


fUnction







problems





conveyor













MN van Aarde

42

CHAPTER 3









CV4 CV3 CV2 CV1







MN van Aarde

43

CHAPTER 3





90 de-g TRANSFBt











MN van Aarde

44

CHAPTER 3


4 mm and 12 mm



Fine K 5mm

Fine N 8mm

Fine A 8mm

Coarse K 25mm

Coarse D 34mm

Coarse S 12 mm

Coarse A 20mm










MN van Aarde

45

CHAPTER 3












MN van Aarde

46

CHAPTER 3












MN van Aarde

47

CHAPTER 3



























MN van Aarde

48

CHAPTER 3



343 Spillag3















cable


MN van Aarde

49

CHAPTER 3









before loading



MN van Aarde

50

CHAPTER 3

















conveyor system










MN van Aarde

51

CHAPTER 3


constant rate







IlmJ



C)


t) cent


~~ Ii ~ ~ g i i ~ 4 1 J yen i


Time







MN van Aarde

52

CHAPTER 3
















MN van Aarde

53

CHAPTER 3




CV11 CV5 Yes






CV31 CV5 Yes

Yes

Yes





No (Mech trip on




No (Feed to CV 2






MN van Aarde

54

CHAPTER 3





than 10000 tlh






10000 tlh







36 CONCLUSION










MN van Aarde

55

CHAPTER 3




















transfer chutes


MN van Aarde

56

CHAPTER 4


RECURRING PROBLEMS


MN van Aarde

57

CHAPTER 4

41 PREFACE




















feeding conveyor






MN van Aarde

58

CHAPTER 4















t4CLIE SECTION

PURGING POSmON







MN van Aarde

59

CHAPTER 4












I ~

j







MN van Aarde

60

CHAPTER 4
















chute








MN van Aarde

61

CHAPTER 4 -__-----__---_----------shy


















MN van Aarde

62

CHAPTER 4

START-UP CHrrlE

DRlBBIlNG CHUTE
















MN van Aarde

63

CHAPTER 4 -__----- ------shy





















hood surface







MN van Aarde

64

-----

CHAPTER 4


70

--- --~ 6 0

5 0

40 ~_

~ 30 g --- a 20 gt

10

00


















MN van Aarde

65

CHAPTER 4


67

66

65

S 64 amp0 g 6 3

V

v-shy ~ ~

ii ~ gt 62

61 I I 60

o 10 20 30 40 50 60



















MN van Aarde

66

CHAPTER 4


chute














M N van Aarde

67

CHAPTER 4




















e = tan- I ( 1 ) (5)

C Ii







MN van Aarde

CHAPTER 4













MN van Aarde

69

CHAPTER 4

WEAR BOX








inside


MN van Aarde

70

CHAPTER 4 ----_----------------shy




















MN van Aarde

71

CHAPTER 4 ------------_ -- - ---------------shy






section as shown in











MN van Aarde

72

CHAPTER 4
















MN van Aarde

73

CHAPTER 4












MN van Aarde

74

CHAPTER 4










46 CONCLUSION








MN van Aarde

75

CHAPTER 4



















MN van Aarde

76

CHAPTER 5




MN van Aarde

CHAPTER 5

51 PREFACE





















MN van Aarde

78

CHAPTER 5












expensive [34]









chute designs







MN van Aarde

79

CHAPTER 5










collision








time [37]


MN van Aarde

80

CHAPTER 5





equipmentshy




segregation


process


of the simulation














MN van Aarde

81

CHAPTERS













of the design










this dissertation


MN van Aarde

82

CHAPTER 5












MN van Aarde

83

CHAPTER 5




























MN van Aarde

84

CHAPTER 5


software of choice





must be rendered


manufacturing







9 Manufacture

10 Installation











M N van Aarde

85

CHAPTER 5




























MN van Aarde

86

CHAPTER 5




























MN van Aarde

87

CHAPTER 5








APPLICATION





correctly





MN van Aarde

CHAPTER 5


ore type
















MN van Aarde

89

CHAPTER 5


by Figure 52








Off-centre loading

L



MN van Aarde

90

CHAPTER 5


Low velocity layer









transfer point










MN van Aarde

91

CHAPTER 5






HOOD LOCATION









I

L



MN van Aarde

92

CHAPTER 5














MN van Aarde

93

CHAPTER 5


Slower material

L














MN van Aarde

94

CHAPTERS ----------------- -------___ _--shy














chute










MN van Aarde

95

CHAPTER 5

Large radius hood



belt

L


Spoon





MN van Aarde

96

CHAPTERS













however minimised

58 CONCLUSION







with OEM







MN van Aarde

97

CHAPTER 5













MN van Aarde

98

CHAPTER 6



MN van Aarde

99

CHAPTER 6




























MN van Aarde

100

CHAPTER 6





























MN van Aarde

101

CHAPTER 6


























design is reduced


MN van Aarde

102

CHAPTER 6







worn conveyors





















MN van Aarde

103

CHAPTER 6








should be examined












parameters


MN van Aarde

104


REFERENCES











10 Jun 2009











MN van Aarde

105

REFERENCES




4037735





18 Jun 2009



access 22 Jun 2009













MN van Aarde

106

REFERENCES






5 Jul 2009


Power Atticle Oct




Material Handling


26 Apr 2010





1(4) Dec



6(1) Feb



MN van Aarde

107








Bionic research






association 1989




Newcastle Australia





Bionic


MN van Aarde

108

REFERENCES



handling 17 Oct





















MN van Aarde

109

REFERENCES















Handling Industry




MN van Aarde

110

ApPENDIXA



MN van Aarde

11-1

ApPENDIX A



























MN van Aarde

112

ApPENDIX A







Liner T

en aJ c

u

I

i

N en aJ c

u

Cf)

en aJ c

u

I en


(f) shy0

T

aJ ~ j 0 0

N aJ ~ j 0 0 i

I Chrome x x x x x

Carbide


x x x x x x94

Alumina

Ceramic i I

Poly x

Urethane I I I

FLOW TEST WORK










The industry 113

MN van Aarde

ApPENDIXA






WEAR TEST WORK







at the same force









LINER SELECTION





MN van Aarde

ApPEND[xA


ceramics





application


MN van Aarde

115

ApPENODlt B



MN van Aarde

116

ApPENDIX B


























MN van Aarde

117

ApPENDIXB















MN van Aarde

118

ACKNOWLEDGEMENTS

ACKNOWLEDGEMENTS


degree







MN van Aarde

vi


TABLE OF CONTENTS

Abstract ii

Samevatting iv

Acknowledgements vi


List of figures ix

List of tables xii

Nomenclature xiii








21 Preface 22





26 Conclusion37


31 Preface 40





36 Conclusion55


MN van Aarde

vii

TABLE OF CONTENTS


41 Preface 58





46 Conclusion75


51 Preface 78





location 92


58 Conclusion 97




References 1 05




MN van Aarde

viii

LIST OF FIGURES

LIST OF FIGURES
























[32] 35






MN van Aarde

ix

LIST OF FIGURES






















feeders [36J 80











MN van Aarde

x

OF FIGURES




MN van Aarde

xi

LIST OF TABLES

LIST OF TABLES





M N van Aarde

xii

---------------------------------

CV

NOMENCLATURE

NOMENCLATURE

SCADA

CCTV

CEMA

DEM

kPa

mm

MSHA

ms

mt

MW

NIOSH

OSHA

RampD

tlh

3D




Conveyor


Kilopascal

Millimetres


Metres per second

Metric Tons

Megawatt



Radius of curvature


Tons per hour

Three Dimensional


MN van Aarde

xiii

CHAPTER 1




MN van Aarde

1

CHAPTER 1













significant

o



MN van Aarde

2

CHAPTER 1



























MN van Aarde

3

CHAPTER 1 - ----~--~--------------~--------




Figure 3








MN van Aarde

4

CHAPTER 1











the most extreme




Sishen entails [8]










11 N van Aarde

5

CHAPTER 1

121 Crushing














requirements



MN van Aarde

6

CHAPTER 1
















MN van Aarde

7

CHAPTER 1











conveyor [10]









used








MN van Aarde

8

CHAPTER 1














MN van Aarde

9

CHAPTER 1










MN van Aarde

10

CHAPTER 1








COVERED










MN van Aarde

11

CHAPTER 1






bull Spillage

bull Blocked chutes







transfer chute






MN van Aarde

CHAPTER 1











MN van Aarde

13

CHAPTER 1 --~ ---------------------------shy





dust emissions

















shown in Figure 14


MN van Aarde

14

CHAPTER 1














MN van Aarde

15

CHAPTER 1










MN van Aarde

16

CHAPTER 1













eliminated [13]




MN van Aarde

17

CHAPTER 1



design























MN van Aarde

CHAPTER 1





performance



















new transfer chutes




MN van Aarde

CHAPTER 1







chapter











facility


MN van Aarde

20

CHAPTER 2



MN van Aarde

21

CHAPTER 2

21 PREFACE





















solution





MN van Aarde

22

CHAPTER 2


catered for


the conveyor




the belt










MN van Aarde

23

CHAPTER 2


Aria Unit

Feed Conveyor

Belt Speed r ms

Belt Width mm


Pulley Width mm



Sight Height Data


Drop Height mm


Receiving Conveyor

Belt Speed ms

Belt Width mm

Belt Thickness mm




Material Properties








Inc are [25]


MN van Aarde

24

CHAPTER 2



























MN van Aarde

25

CHAPTER 2














clean [25]










M N van Aarde

26

CHAPTER 2








possible [25]


CONSTRAINTS




handled [1]





I I




L J -





MN van Aarde

27

CHAPTER 2



















MN van Aarde

28

CHAPTER 2















start up



MN van Aarde

29

CHAPTER 2













x

Vo

- ImpactPlate



MN van Aarde

30

CHAPTER 2





















MN van Aarde

31

CHAPTER 2 ---~----------------






reduced [29]


(1)






v = material speed










MN van Aarde

CHAPTER 2

[1 + ( gx )]15 R = vcos8

c (2)

vcos8

Where


v == material speed




















MN van Aarde

33

CHAPTER 2




























MN van Aarde

34

CHAPTER 2


_ IIU _ Im _ I rn _ 171-111 _ u n _ ~ l

_ 4 ~

_ 41 _ 4


~ 1m bull UI2








MN van Aarde

35

CHAPTER 2











is determined and

(4)


MN van Aarde

36

CHAPTER 2

Mass Flow Rate Omh










26 CONCLUSION






MN van Aarde

37

CHAPTER 2










facility limits







MN van Aarde

38

CHAPTER 3


MN van Aarde



39

CHAPTER 3

31 PREFACE




















chute

32 TEST METHODOLOGY






MN van Aarde

40

CHAPTER 3





















sidewalls






MN van Aarde

CHAPTER 3


fUnction







problems





conveyor













MN van Aarde

42

CHAPTER 3









CV4 CV3 CV2 CV1







MN van Aarde

43

CHAPTER 3





90 de-g TRANSFBt











MN van Aarde

44

CHAPTER 3


4 mm and 12 mm



Fine K 5mm

Fine N 8mm

Fine A 8mm

Coarse K 25mm

Coarse D 34mm

Coarse S 12 mm

Coarse A 20mm










MN van Aarde

45

CHAPTER 3












MN van Aarde

46

CHAPTER 3












MN van Aarde

47

CHAPTER 3



























MN van Aarde

48

CHAPTER 3



343 Spillag3















cable


MN van Aarde

49

CHAPTER 3









before loading



MN van Aarde

50

CHAPTER 3

















conveyor system










MN van Aarde

51

CHAPTER 3


constant rate







IlmJ



C)


t) cent


~~ Ii ~ ~ g i i ~ 4 1 J yen i


Time







MN van Aarde

52

CHAPTER 3
















MN van Aarde

53

CHAPTER 3




CV11 CV5 Yes






CV31 CV5 Yes

Yes

Yes





No (Mech trip on




No (Feed to CV 2






MN van Aarde

54

CHAPTER 3





than 10000 tlh






10000 tlh







36 CONCLUSION










MN van Aarde

55

CHAPTER 3




















transfer chutes


MN van Aarde

56

CHAPTER 4


RECURRING PROBLEMS


MN van Aarde

57

CHAPTER 4

41 PREFACE




















feeding conveyor






MN van Aarde

58

CHAPTER 4















t4CLIE SECTION

PURGING POSmON







MN van Aarde

59

CHAPTER 4












I ~

j







MN van Aarde

60

CHAPTER 4
















chute








MN van Aarde

61

CHAPTER 4 -__-----__---_----------shy


















MN van Aarde

62

CHAPTER 4

START-UP CHrrlE

DRlBBIlNG CHUTE
















MN van Aarde

63

CHAPTER 4 -__----- ------shy





















hood surface







MN van Aarde

64

-----

CHAPTER 4


70

--- --~ 6 0

5 0

40 ~_

~ 30 g --- a 20 gt

10

00


















MN van Aarde

65

CHAPTER 4


67

66

65

S 64 amp0 g 6 3

V

v-shy ~ ~

ii ~ gt 62

61 I I 60

o 10 20 30 40 50 60



















MN van Aarde

66

CHAPTER 4


chute














M N van Aarde

67

CHAPTER 4




















e = tan- I ( 1 ) (5)

C Ii







MN van Aarde

CHAPTER 4













MN van Aarde

69

CHAPTER 4

WEAR BOX








inside


MN van Aarde

70

CHAPTER 4 ----_----------------shy




















MN van Aarde

71

CHAPTER 4 ------------_ -- - ---------------shy






section as shown in











MN van Aarde

72

CHAPTER 4
















MN van Aarde

73

CHAPTER 4












MN van Aarde

74

CHAPTER 4










46 CONCLUSION








MN van Aarde

75

CHAPTER 4



















MN van Aarde

76

CHAPTER 5




MN van Aarde

CHAPTER 5

51 PREFACE





















MN van Aarde

78

CHAPTER 5












expensive [34]









chute designs







MN van Aarde

79

CHAPTER 5










collision








time [37]


MN van Aarde

80

CHAPTER 5





equipmentshy




segregation


process


of the simulation














MN van Aarde

81

CHAPTERS













of the design










this dissertation


MN van Aarde

82

CHAPTER 5












MN van Aarde

83

CHAPTER 5




























MN van Aarde

84

CHAPTER 5


software of choice





must be rendered


manufacturing







9 Manufacture

10 Installation











M N van Aarde

85

CHAPTER 5




























MN van Aarde

86

CHAPTER 5




























MN van Aarde

87

CHAPTER 5








APPLICATION





correctly





MN van Aarde

CHAPTER 5


ore type
















MN van Aarde

89

CHAPTER 5


by Figure 52








Off-centre loading

L



MN van Aarde

90

CHAPTER 5


Low velocity layer









transfer point










MN van Aarde

91

CHAPTER 5






HOOD LOCATION









I

L



MN van Aarde

92

CHAPTER 5














MN van Aarde

93

CHAPTER 5


Slower material

L














MN van Aarde

94

CHAPTERS ----------------- -------___ _--shy














chute










MN van Aarde

95

CHAPTER 5

Large radius hood



belt

L


Spoon





MN van Aarde

96

CHAPTERS













however minimised

58 CONCLUSION







with OEM







MN van Aarde

97

CHAPTER 5













MN van Aarde

98

CHAPTER 6



MN van Aarde

99

CHAPTER 6




























MN van Aarde

100

CHAPTER 6





























MN van Aarde

101

CHAPTER 6


























design is reduced


MN van Aarde

102

CHAPTER 6







worn conveyors





















MN van Aarde

103

CHAPTER 6








should be examined












parameters


MN van Aarde

104


REFERENCES











10 Jun 2009











MN van Aarde

105

REFERENCES




4037735





18 Jun 2009



access 22 Jun 2009













MN van Aarde

106

REFERENCES






5 Jul 2009


Power Atticle Oct




Material Handling


26 Apr 2010





1(4) Dec



6(1) Feb



MN van Aarde

107








Bionic research






association 1989




Newcastle Australia





Bionic


MN van Aarde

108

REFERENCES



handling 17 Oct





















MN van Aarde

109

REFERENCES















Handling Industry




MN van Aarde

110

ApPENDIXA



MN van Aarde

11-1

ApPENDIX A



























MN van Aarde

112

ApPENDIX A







Liner T

en aJ c

u

I

i

N en aJ c

u

Cf)

en aJ c

u

I en


(f) shy0

T

aJ ~ j 0 0

N aJ ~ j 0 0 i

I Chrome x x x x x

Carbide


x x x x x x94

Alumina

Ceramic i I

Poly x

Urethane I I I

FLOW TEST WORK










The industry 113

MN van Aarde

ApPENDIXA






WEAR TEST WORK







at the same force









LINER SELECTION





MN van Aarde

ApPEND[xA


ceramics





application


MN van Aarde

115

ApPENODlt B



MN van Aarde

116

ApPENDIX B


























MN van Aarde

117

ApPENDIXB















MN van Aarde

118


TABLE OF CONTENTS

Abstract ii

Samevatting iv

Acknowledgements vi


List of figures ix

List of tables xii

Nomenclature xiii








21 Preface 22





26 Conclusion37


31 Preface 40





36 Conclusion55


MN van Aarde

vii

TABLE OF CONTENTS


41 Preface 58





46 Conclusion75


51 Preface 78





location 92


58 Conclusion 97




References 1 05




MN van Aarde

viii

LIST OF FIGURES

LIST OF FIGURES
























[32] 35






MN van Aarde

ix

LIST OF FIGURES






















feeders [36J 80











MN van Aarde

x

OF FIGURES




MN van Aarde

xi

LIST OF TABLES

LIST OF TABLES





M N van Aarde

xii

---------------------------------

CV

NOMENCLATURE

NOMENCLATURE

SCADA

CCTV

CEMA

DEM

kPa

mm

MSHA

ms

mt

MW

NIOSH

OSHA

RampD

tlh

3D




Conveyor


Kilopascal

Millimetres


Metres per second

Metric Tons

Megawatt



Radius of curvature


Tons per hour

Three Dimensional


MN van Aarde

xiii

CHAPTER 1




MN van Aarde

1

CHAPTER 1













significant

o



MN van Aarde

2

CHAPTER 1



























MN van Aarde

3

CHAPTER 1 - ----~--~--------------~--------




Figure 3








MN van Aarde

4

CHAPTER 1











the most extreme




Sishen entails [8]










11 N van Aarde

5

CHAPTER 1

121 Crushing














requirements



MN van Aarde

6

CHAPTER 1
















MN van Aarde

7

CHAPTER 1











conveyor [10]









used








MN van Aarde

8

CHAPTER 1














MN van Aarde

9

CHAPTER 1










MN van Aarde

10

CHAPTER 1








COVERED










MN van Aarde

11

CHAPTER 1






bull Spillage

bull Blocked chutes







transfer chute






MN van Aarde

CHAPTER 1











MN van Aarde

13

CHAPTER 1 --~ ---------------------------shy





dust emissions

















shown in Figure 14


MN van Aarde

14

CHAPTER 1














MN van Aarde

15

CHAPTER 1










MN van Aarde

16

CHAPTER 1













eliminated [13]




MN van Aarde

17

CHAPTER 1



design























MN van Aarde

CHAPTER 1





performance



















new transfer chutes




MN van Aarde

CHAPTER 1







chapter











facility


MN van Aarde

20

CHAPTER 2



MN van Aarde

21

CHAPTER 2

21 PREFACE





















solution





MN van Aarde

22

CHAPTER 2


catered for


the conveyor




the belt










MN van Aarde

23

CHAPTER 2


Aria Unit

Feed Conveyor

Belt Speed r ms

Belt Width mm


Pulley Width mm



Sight Height Data


Drop Height mm


Receiving Conveyor

Belt Speed ms

Belt Width mm

Belt Thickness mm




Material Properties








Inc are [25]


MN van Aarde

24

CHAPTER 2



























MN van Aarde

25

CHAPTER 2














clean [25]










M N van Aarde

26

CHAPTER 2








possible [25]


CONSTRAINTS




handled [1]





I I




L J -





MN van Aarde

27

CHAPTER 2



















MN van Aarde

28

CHAPTER 2















start up



MN van Aarde

29

CHAPTER 2













x

Vo

- ImpactPlate



MN van Aarde

30

CHAPTER 2





















MN van Aarde

31

CHAPTER 2 ---~----------------






reduced [29]


(1)






v = material speed










MN van Aarde

CHAPTER 2

[1 + ( gx )]15 R = vcos8

c (2)

vcos8

Where


v == material speed




















MN van Aarde

33

CHAPTER 2




























MN van Aarde

34

CHAPTER 2


_ IIU _ Im _ I rn _ 171-111 _ u n _ ~ l

_ 4 ~

_ 41 _ 4


~ 1m bull UI2








MN van Aarde

35

CHAPTER 2











is determined and

(4)


MN van Aarde

36

CHAPTER 2

Mass Flow Rate Omh










26 CONCLUSION






MN van Aarde

37

CHAPTER 2










facility limits







MN van Aarde

38

CHAPTER 3


MN van Aarde



39

CHAPTER 3

31 PREFACE




















chute

32 TEST METHODOLOGY






MN van Aarde

40

CHAPTER 3





















sidewalls






MN van Aarde

CHAPTER 3


fUnction







problems





conveyor













MN van Aarde

42

CHAPTER 3









CV4 CV3 CV2 CV1







MN van Aarde

43

CHAPTER 3





90 de-g TRANSFBt











MN van Aarde

44

CHAPTER 3


4 mm and 12 mm



Fine K 5mm

Fine N 8mm

Fine A 8mm

Coarse K 25mm

Coarse D 34mm

Coarse S 12 mm

Coarse A 20mm










MN van Aarde

45

CHAPTER 3












MN van Aarde

46

CHAPTER 3












MN van Aarde

47

CHAPTER 3



























MN van Aarde

48

CHAPTER 3



343 Spillag3















cable


MN van Aarde

49

CHAPTER 3









before loading



MN van Aarde

50

CHAPTER 3

















conveyor system










MN van Aarde

51

CHAPTER 3


constant rate







IlmJ



C)


t) cent


~~ Ii ~ ~ g i i ~ 4 1 J yen i


Time







MN van Aarde

52

CHAPTER 3
















MN van Aarde

53

CHAPTER 3




CV11 CV5 Yes






CV31 CV5 Yes

Yes

Yes





No (Mech trip on




No (Feed to CV 2






MN van Aarde

54

CHAPTER 3





than 10000 tlh






10000 tlh







36 CONCLUSION










MN van Aarde

55

CHAPTER 3




















transfer chutes


MN van Aarde

56

CHAPTER 4


RECURRING PROBLEMS


MN van Aarde

57

CHAPTER 4

41 PREFACE




















feeding conveyor






MN van Aarde

58

CHAPTER 4















t4CLIE SECTION

PURGING POSmON







MN van Aarde

59

CHAPTER 4












I ~

j







MN van Aarde

60

CHAPTER 4
















chute








MN van Aarde

61

CHAPTER 4 -__-----__---_----------shy


















MN van Aarde

62

CHAPTER 4

START-UP CHrrlE

DRlBBIlNG CHUTE
















MN van Aarde

63

CHAPTER 4 -__----- ------shy





















hood surface







MN van Aarde

64

-----

CHAPTER 4


70

--- --~ 6 0

5 0

40 ~_

~ 30 g --- a 20 gt

10

00


















MN van Aarde

65

CHAPTER 4


67

66

65

S 64 amp0 g 6 3

V

v-shy ~ ~

ii ~ gt 62

61 I I 60

o 10 20 30 40 50 60



















MN van Aarde

66

CHAPTER 4


chute














M N van Aarde

67

CHAPTER 4




















e = tan- I ( 1 ) (5)

C Ii







MN van Aarde

CHAPTER 4













MN van Aarde

69

CHAPTER 4

WEAR BOX








inside


MN van Aarde

70

CHAPTER 4 ----_----------------shy




















MN van Aarde

71

CHAPTER 4 ------------_ -- - ---------------shy






section as shown in











MN van Aarde

72

CHAPTER 4
















MN van Aarde

73

CHAPTER 4












MN van Aarde

74

CHAPTER 4










46 CONCLUSION








MN van Aarde

75

CHAPTER 4



















MN van Aarde

76

CHAPTER 5




MN van Aarde

CHAPTER 5

51 PREFACE





















MN van Aarde

78

CHAPTER 5












expensive [34]









chute designs







MN van Aarde

79

CHAPTER 5










collision








time [37]


MN van Aarde

80

CHAPTER 5





equipmentshy




segregation


process


of the simulation














MN van Aarde

81

CHAPTERS













of the design










this dissertation


MN van Aarde

82

CHAPTER 5












MN van Aarde

83

CHAPTER 5




























MN van Aarde

84

CHAPTER 5


software of choice





must be rendered


manufacturing







9 Manufacture

10 Installation











M N van Aarde

85

CHAPTER 5




























MN van Aarde

86

CHAPTER 5




























MN van Aarde

87

CHAPTER 5








APPLICATION





correctly





MN van Aarde

CHAPTER 5


ore type
















MN van Aarde

89

CHAPTER 5


by Figure 52








Off-centre loading

L



MN van Aarde

90

CHAPTER 5


Low velocity layer









transfer point










MN van Aarde

91

CHAPTER 5






HOOD LOCATION









I

L



MN van Aarde

92

CHAPTER 5














MN van Aarde

93

CHAPTER 5


Slower material

L














MN van Aarde

94

CHAPTERS ----------------- -------___ _--shy














chute










MN van Aarde

95

CHAPTER 5

Large radius hood



belt

L


Spoon





MN van Aarde

96

CHAPTERS













however minimised

58 CONCLUSION







with OEM







MN van Aarde

97

CHAPTER 5













MN van Aarde

98

CHAPTER 6



MN van Aarde

99

CHAPTER 6




























MN van Aarde

100

CHAPTER 6





























MN van Aarde

101

CHAPTER 6


























design is reduced


MN van Aarde

102

CHAPTER 6







worn conveyors





















MN van Aarde

103

CHAPTER 6








should be examined












parameters


MN van Aarde

104


REFERENCES











10 Jun 2009











MN van Aarde

105

REFERENCES




4037735





18 Jun 2009



access 22 Jun 2009













MN van Aarde

106

REFERENCES






5 Jul 2009


Power Atticle Oct




Material Handling


26 Apr 2010





1(4) Dec



6(1) Feb



MN van Aarde

107








Bionic research






association 1989




Newcastle Australia





Bionic


MN van Aarde

108

REFERENCES



handling 17 Oct





















MN van Aarde

109

REFERENCES















Handling Industry




MN van Aarde

110

ApPENDIXA



MN van Aarde

11-1

ApPENDIX A



























MN van Aarde

112

ApPENDIX A







Liner T

en aJ c

u

I

i

N en aJ c

u

Cf)

en aJ c

u

I en


(f) shy0

T

aJ ~ j 0 0

N aJ ~ j 0 0 i

I Chrome x x x x x

Carbide


x x x x x x94

Alumina

Ceramic i I

Poly x

Urethane I I I

FLOW TEST WORK










The industry 113

MN van Aarde

ApPENDIXA






WEAR TEST WORK







at the same force









LINER SELECTION





MN van Aarde

ApPEND[xA


ceramics





application


MN van Aarde

115

ApPENODlt B



MN van Aarde

116

ApPENDIX B


























MN van Aarde

117

ApPENDIXB















MN van Aarde

118

TABLE OF CONTENTS


41 Preface 58





46 Conclusion75


51 Preface 78





location 92


58 Conclusion 97




References 1 05




MN van Aarde

viii

LIST OF FIGURES

LIST OF FIGURES
























[32] 35






MN van Aarde

ix

LIST OF FIGURES






















feeders [36J 80











MN van Aarde

x

OF FIGURES




MN van Aarde

xi

LIST OF TABLES

LIST OF TABLES





M N van Aarde

xii

---------------------------------

CV

NOMENCLATURE

NOMENCLATURE

SCADA

CCTV

CEMA

DEM

kPa

mm

MSHA

ms

mt

MW

NIOSH

OSHA

RampD

tlh

3D




Conveyor


Kilopascal

Millimetres


Metres per second

Metric Tons

Megawatt



Radius of curvature


Tons per hour

Three Dimensional


MN van Aarde

xiii

CHAPTER 1




MN van Aarde

1

CHAPTER 1













significant

o



MN van Aarde

2

CHAPTER 1



























MN van Aarde

3

CHAPTER 1 - ----~--~--------------~--------




Figure 3








MN van Aarde

4

CHAPTER 1











the most extreme




Sishen entails [8]










11 N van Aarde

5

CHAPTER 1

121 Crushing














requirements



MN van Aarde

6

CHAPTER 1
















MN van Aarde

7

CHAPTER 1











conveyor [10]









used








MN van Aarde

8

CHAPTER 1














MN van Aarde

9

CHAPTER 1










MN van Aarde

10

CHAPTER 1








COVERED










MN van Aarde

11

CHAPTER 1






bull Spillage

bull Blocked chutes







transfer chute






MN van Aarde

CHAPTER 1











MN van Aarde

13

CHAPTER 1 --~ ---------------------------shy





dust emissions

















shown in Figure 14


MN van Aarde

14

CHAPTER 1














MN van Aarde

15

CHAPTER 1










MN van Aarde

16

CHAPTER 1













eliminated [13]




MN van Aarde

17

CHAPTER 1



design























MN van Aarde

CHAPTER 1





performance



















new transfer chutes




MN van Aarde

CHAPTER 1







chapter











facility


MN van Aarde

20

CHAPTER 2



MN van Aarde

21

CHAPTER 2

21 PREFACE





















solution





MN van Aarde

22

CHAPTER 2


catered for


the conveyor




the belt










MN van Aarde

23

CHAPTER 2


Aria Unit

Feed Conveyor

Belt Speed r ms

Belt Width mm


Pulley Width mm



Sight Height Data


Drop Height mm


Receiving Conveyor

Belt Speed ms

Belt Width mm

Belt Thickness mm




Material Properties








Inc are [25]


MN van Aarde

24

CHAPTER 2



























MN van Aarde

25

CHAPTER 2














clean [25]










M N van Aarde

26

CHAPTER 2








possible [25]


CONSTRAINTS




handled [1]





I I




L J -





MN van Aarde

27

CHAPTER 2



















MN van Aarde

28

CHAPTER 2















start up



MN van Aarde

29

CHAPTER 2













x

Vo

- ImpactPlate



MN van Aarde

30

CHAPTER 2





















MN van Aarde

31

CHAPTER 2 ---~----------------






reduced [29]


(1)






v = material speed










MN van Aarde

CHAPTER 2

[1 + ( gx )]15 R = vcos8

c (2)

vcos8

Where


v == material speed




















MN van Aarde

33

CHAPTER 2




























MN van Aarde

34

CHAPTER 2


_ IIU _ Im _ I rn _ 171-111 _ u n _ ~ l

_ 4 ~

_ 41 _ 4


~ 1m bull UI2








MN van Aarde

35

CHAPTER 2











is determined and

(4)


MN van Aarde

36

CHAPTER 2

Mass Flow Rate Omh










26 CONCLUSION






MN van Aarde

37

CHAPTER 2










facility limits







MN van Aarde

38

CHAPTER 3


MN van Aarde



39

CHAPTER 3

31 PREFACE




















chute

32 TEST METHODOLOGY






MN van Aarde

40

CHAPTER 3





















sidewalls






MN van Aarde

CHAPTER 3


fUnction







problems





conveyor













MN van Aarde

42

CHAPTER 3









CV4 CV3 CV2 CV1







MN van Aarde

43

CHAPTER 3





90 de-g TRANSFBt











MN van Aarde

44

CHAPTER 3


4 mm and 12 mm



Fine K 5mm

Fine N 8mm

Fine A 8mm

Coarse K 25mm

Coarse D 34mm

Coarse S 12 mm

Coarse A 20mm










MN van Aarde

45

CHAPTER 3












MN van Aarde

46

CHAPTER 3












MN van Aarde

47

CHAPTER 3



























MN van Aarde

48

CHAPTER 3



343 Spillag3















cable


MN van Aarde

49

CHAPTER 3









before loading



MN van Aarde

50

CHAPTER 3

















conveyor system










MN van Aarde

51

CHAPTER 3


constant rate







IlmJ



C)


t) cent


~~ Ii ~ ~ g i i ~ 4 1 J yen i


Time







MN van Aarde

52

CHAPTER 3
















MN van Aarde

53

CHAPTER 3




CV11 CV5 Yes






CV31 CV5 Yes

Yes

Yes





No (Mech trip on




No (Feed to CV 2






MN van Aarde

54

CHAPTER 3





than 10000 tlh






10000 tlh







36 CONCLUSION










MN van Aarde

55

CHAPTER 3




















transfer chutes


MN van Aarde

56

CHAPTER 4


RECURRING PROBLEMS


MN van Aarde

57

CHAPTER 4

41 PREFACE




















feeding conveyor






MN van Aarde

58

CHAPTER 4















t4CLIE SECTION

PURGING POSmON







MN van Aarde

59

CHAPTER 4












I ~

j







MN van Aarde

60

CHAPTER 4
















chute








MN van Aarde

61

CHAPTER 4 -__-----__---_----------shy


















MN van Aarde

62

CHAPTER 4

START-UP CHrrlE

DRlBBIlNG CHUTE
















MN van Aarde

63

CHAPTER 4 -__----- ------shy





















hood surface







MN van Aarde

64

-----

CHAPTER 4


70

--- --~ 6 0

5 0

40 ~_

~ 30 g --- a 20 gt

10

00


















MN van Aarde

65

CHAPTER 4


67

66

65

S 64 amp0 g 6 3

V

v-shy ~ ~

ii ~ gt 62

61 I I 60

o 10 20 30 40 50 60



















MN van Aarde

66

CHAPTER 4


chute














M N van Aarde

67

CHAPTER 4




















e = tan- I ( 1 ) (5)

C Ii







MN van Aarde

CHAPTER 4













MN van Aarde

69

CHAPTER 4

WEAR BOX








inside


MN van Aarde

70

CHAPTER 4 ----_----------------shy




















MN van Aarde

71

CHAPTER 4 ------------_ -- - ---------------shy






section as shown in











MN van Aarde

72

CHAPTER 4
















MN van Aarde

73

CHAPTER 4












MN van Aarde

74

CHAPTER 4










46 CONCLUSION








MN van Aarde

75

CHAPTER 4



















MN van Aarde

76

CHAPTER 5




MN van Aarde

CHAPTER 5

51 PREFACE





















MN van Aarde

78

CHAPTER 5












expensive [34]









chute designs







MN van Aarde

79

CHAPTER 5










collision








time [37]


MN van Aarde

80

CHAPTER 5





equipmentshy




segregation


process


of the simulation














MN van Aarde

81

CHAPTERS













of the design










this dissertation


MN van Aarde

82

CHAPTER 5












MN van Aarde

83

CHAPTER 5




























MN van Aarde

84

CHAPTER 5


software of choice





must be rendered


manufacturing







9 Manufacture

10 Installation











M N van Aarde

85

CHAPTER 5




























MN van Aarde

86

CHAPTER 5




























MN van Aarde

87

CHAPTER 5








APPLICATION





correctly





MN van Aarde

CHAPTER 5


ore type
















MN van Aarde

89

CHAPTER 5


by Figure 52








Off-centre loading

L



MN van Aarde

90

CHAPTER 5


Low velocity layer









transfer point










MN van Aarde

91

CHAPTER 5






HOOD LOCATION









I

L



MN van Aarde

92

CHAPTER 5














MN van Aarde

93

CHAPTER 5


Slower material

L














MN van Aarde

94

CHAPTERS ----------------- -------___ _--shy














chute










MN van Aarde

95

CHAPTER 5

Large radius hood



belt

L


Spoon





MN van Aarde

96

CHAPTERS













however minimised

58 CONCLUSION







with OEM







MN van Aarde

97

CHAPTER 5













MN van Aarde

98

CHAPTER 6



MN van Aarde

99

CHAPTER 6




























MN van Aarde

100

CHAPTER 6





























MN van Aarde

101

CHAPTER 6


























design is reduced


MN van Aarde

102

CHAPTER 6







worn conveyors





















MN van Aarde

103

CHAPTER 6








should be examined












parameters


MN van Aarde

104


REFERENCES











10 Jun 2009











MN van Aarde

105

REFERENCES




4037735





18 Jun 2009



access 22 Jun 2009













MN van Aarde

106

REFERENCES






5 Jul 2009


Power Atticle Oct




Material Handling


26 Apr 2010





1(4) Dec



6(1) Feb



MN van Aarde

107








Bionic research






association 1989




Newcastle Australia





Bionic


MN van Aarde

108

REFERENCES



handling 17 Oct





















MN van Aarde

109

REFERENCES















Handling Industry




MN van Aarde

110

ApPENDIXA



MN van Aarde

11-1

ApPENDIX A



























MN van Aarde

112

ApPENDIX A







Liner T

en aJ c

u

I

i

N en aJ c

u

Cf)

en aJ c

u

I en


(f) shy0

T

aJ ~ j 0 0

N aJ ~ j 0 0 i

I Chrome x x x x x

Carbide


x x x x x x94

Alumina

Ceramic i I

Poly x

Urethane I I I

FLOW TEST WORK










The industry 113

MN van Aarde

ApPENDIXA






WEAR TEST WORK







at the same force









LINER SELECTION





MN van Aarde

ApPEND[xA


ceramics





application


MN van Aarde

115

ApPENODlt B



MN van Aarde

116

ApPENDIX B


























MN van Aarde

117

ApPENDIXB















MN van Aarde

118

LIST OF FIGURES

LIST OF FIGURES
























[32] 35






MN van Aarde

ix

LIST OF FIGURES






















feeders [36J 80











MN van Aarde

x

OF FIGURES




MN van Aarde

xi

LIST OF TABLES

LIST OF TABLES





M N van Aarde

xii

---------------------------------

CV

NOMENCLATURE

NOMENCLATURE

SCADA

CCTV

CEMA

DEM

kPa

mm

MSHA

ms

mt

MW

NIOSH

OSHA

RampD

tlh

3D




Conveyor


Kilopascal

Millimetres


Metres per second

Metric Tons

Megawatt



Radius of curvature


Tons per hour

Three Dimensional


MN van Aarde

xiii

CHAPTER 1




MN van Aarde

1

CHAPTER 1













significant

o



MN van Aarde

2

CHAPTER 1



























MN van Aarde

3

CHAPTER 1 - ----~--~--------------~--------




Figure 3








MN van Aarde

4

CHAPTER 1











the most extreme




Sishen entails [8]










11 N van Aarde

5

CHAPTER 1

121 Crushing














requirements



MN van Aarde

6

CHAPTER 1
















MN van Aarde

7

CHAPTER 1











conveyor [10]









used








MN van Aarde

8

CHAPTER 1














MN van Aarde

9

CHAPTER 1










MN van Aarde

10

CHAPTER 1








COVERED










MN van Aarde

11

CHAPTER 1






bull Spillage

bull Blocked chutes







transfer chute






MN van Aarde

CHAPTER 1











MN van Aarde

13

CHAPTER 1 --~ ---------------------------shy





dust emissions

















shown in Figure 14


MN van Aarde

14

CHAPTER 1














MN van Aarde

15

CHAPTER 1










MN van Aarde

16

CHAPTER 1













eliminated [13]




MN van Aarde

17

CHAPTER 1



design























MN van Aarde

CHAPTER 1





performance



















new transfer chutes




MN van Aarde

CHAPTER 1







chapter











facility


MN van Aarde

20

CHAPTER 2



MN van Aarde

21

CHAPTER 2

21 PREFACE





















solution





MN van Aarde

22

CHAPTER 2


catered for


the conveyor




the belt










MN van Aarde

23

CHAPTER 2


Aria Unit

Feed Conveyor

Belt Speed r ms

Belt Width mm


Pulley Width mm



Sight Height Data


Drop Height mm


Receiving Conveyor

Belt Speed ms

Belt Width mm

Belt Thickness mm




Material Properties








Inc are [25]


MN van Aarde

24

CHAPTER 2



























MN van Aarde

25

CHAPTER 2














clean [25]










M N van Aarde

26

CHAPTER 2








possible [25]


CONSTRAINTS




handled [1]





I I




L J -





MN van Aarde

27

CHAPTER 2



















MN van Aarde

28

CHAPTER 2















start up



MN van Aarde

29

CHAPTER 2













x

Vo

- ImpactPlate



MN van Aarde

30

CHAPTER 2





















MN van Aarde

31

CHAPTER 2 ---~----------------






reduced [29]


(1)






v = material speed










MN van Aarde

CHAPTER 2

[1 + ( gx )]15 R = vcos8

c (2)

vcos8

Where


v == material speed




















MN van Aarde

33

CHAPTER 2




























MN van Aarde

34

CHAPTER 2


_ IIU _ Im _ I rn _ 171-111 _ u n _ ~ l

_ 4 ~

_ 41 _ 4


~ 1m bull UI2








MN van Aarde

35

CHAPTER 2











is determined and

(4)


MN van Aarde

36

CHAPTER 2

Mass Flow Rate Omh










26 CONCLUSION






MN van Aarde

37

CHAPTER 2










facility limits







MN van Aarde

38

CHAPTER 3


MN van Aarde



39

CHAPTER 3

31 PREFACE




















chute

32 TEST METHODOLOGY






MN van Aarde

40

CHAPTER 3





















sidewalls






MN van Aarde

CHAPTER 3


fUnction







problems





conveyor













MN van Aarde

42

CHAPTER 3









CV4 CV3 CV2 CV1







MN van Aarde

43

CHAPTER 3





90 de-g TRANSFBt











MN van Aarde

44

CHAPTER 3


4 mm and 12 mm



Fine K 5mm

Fine N 8mm

Fine A 8mm

Coarse K 25mm

Coarse D 34mm

Coarse S 12 mm

Coarse A 20mm










MN van Aarde

45

CHAPTER 3












MN van Aarde

46

CHAPTER 3












MN van Aarde

47

CHAPTER 3



























MN van Aarde

48

CHAPTER 3



343 Spillag3















cable


MN van Aarde

49

CHAPTER 3









before loading



MN van Aarde

50

CHAPTER 3

















conveyor system










MN van Aarde

51

CHAPTER 3


constant rate







IlmJ



C)


t) cent


~~ Ii ~ ~ g i i ~ 4 1 J yen i


Time







MN van Aarde

52

CHAPTER 3
















MN van Aarde

53

CHAPTER 3




CV11 CV5 Yes






CV31 CV5 Yes

Yes

Yes





No (Mech trip on




No (Feed to CV 2






MN van Aarde

54

CHAPTER 3





than 10000 tlh






10000 tlh







36 CONCLUSION










MN van Aarde

55

CHAPTER 3




















transfer chutes


MN van Aarde

56

CHAPTER 4


RECURRING PROBLEMS


MN van Aarde

57

CHAPTER 4

41 PREFACE




















feeding conveyor






MN van Aarde

58

CHAPTER 4















t4CLIE SECTION

PURGING POSmON







MN van Aarde

59

CHAPTER 4












I ~

j







MN van Aarde

60

CHAPTER 4
















chute








MN van Aarde

61

CHAPTER 4 -__-----__---_----------shy


















MN van Aarde

62

CHAPTER 4

START-UP CHrrlE

DRlBBIlNG CHUTE
















MN van Aarde

63

CHAPTER 4 -__----- ------shy





















hood surface







MN van Aarde

64

-----

CHAPTER 4


70

--- --~ 6 0

5 0

40 ~_

~ 30 g --- a 20 gt

10

00


















MN van Aarde

65

CHAPTER 4


67

66

65

S 64 amp0 g 6 3

V

v-shy ~ ~

ii ~ gt 62

61 I I 60

o 10 20 30 40 50 60



















MN van Aarde

66

CHAPTER 4


chute














M N van Aarde

67

CHAPTER 4




















e = tan- I ( 1 ) (5)

C Ii







MN van Aarde

CHAPTER 4













MN van Aarde

69

CHAPTER 4

WEAR BOX








inside


MN van Aarde

70

CHAPTER 4 ----_----------------shy




















MN van Aarde

71

CHAPTER 4 ------------_ -- - ---------------shy






section as shown in











MN van Aarde

72

CHAPTER 4
















MN van Aarde

73

CHAPTER 4












MN van Aarde

74

CHAPTER 4










46 CONCLUSION








MN van Aarde

75

CHAPTER 4



















MN van Aarde

76

CHAPTER 5




MN van Aarde

CHAPTER 5

51 PREFACE





















MN van Aarde

78

CHAPTER 5












expensive [34]









chute designs







MN van Aarde

79

CHAPTER 5










collision








time [37]


MN van Aarde

80

CHAPTER 5





equipmentshy




segregation


process


of the simulation














MN van Aarde

81

CHAPTERS













of the design










this dissertation


MN van Aarde

82

CHAPTER 5












MN van Aarde

83

CHAPTER 5




























MN van Aarde

84

CHAPTER 5


software of choice





must be rendered


manufacturing







9 Manufacture

10 Installation











M N van Aarde

85

CHAPTER 5




























MN van Aarde

86

CHAPTER 5




























MN van Aarde

87

CHAPTER 5








APPLICATION





correctly





MN van Aarde

CHAPTER 5


ore type
















MN van Aarde

89

CHAPTER 5


by Figure 52








Off-centre loading

L



MN van Aarde

90

CHAPTER 5


Low velocity layer









transfer point










MN van Aarde

91

CHAPTER 5






HOOD LOCATION









I

L



MN van Aarde

92

CHAPTER 5














MN van Aarde

93

CHAPTER 5


Slower material

L














MN van Aarde

94

CHAPTERS ----------------- -------___ _--shy














chute










MN van Aarde

95

CHAPTER 5

Large radius hood



belt

L


Spoon





MN van Aarde

96

CHAPTERS













however minimised

58 CONCLUSION







with OEM







MN van Aarde

97

CHAPTER 5













MN van Aarde

98

CHAPTER 6



MN van Aarde

99

CHAPTER 6




























MN van Aarde

100

CHAPTER 6





























MN van Aarde

101

CHAPTER 6


























design is reduced


MN van Aarde

102

CHAPTER 6







worn conveyors





















MN van Aarde

103

CHAPTER 6








should be examined












parameters


MN van Aarde

104


REFERENCES











10 Jun 2009











MN van Aarde

105

REFERENCES




4037735





18 Jun 2009



access 22 Jun 2009













MN van Aarde

106

REFERENCES






5 Jul 2009


Power Atticle Oct




Material Handling


26 Apr 2010





1(4) Dec



6(1) Feb



MN van Aarde

107








Bionic research






association 1989




Newcastle Australia





Bionic


MN van Aarde

108

REFERENCES



handling 17 Oct





















MN van Aarde

109

REFERENCES















Handling Industry




MN van Aarde

110

ApPENDIXA



MN van Aarde

11-1

ApPENDIX A



























MN van Aarde

112

ApPENDIX A







Liner T

en aJ c

u

I

i

N en aJ c

u

Cf)

en aJ c

u

I en


(f) shy0

T

aJ ~ j 0 0

N aJ ~ j 0 0 i

I Chrome x x x x x

Carbide


x x x x x x94

Alumina

Ceramic i I

Poly x

Urethane I I I

FLOW TEST WORK










The industry 113

MN van Aarde

ApPENDIXA






WEAR TEST WORK







at the same force









LINER SELECTION





MN van Aarde

ApPEND[xA


ceramics





application


MN van Aarde

115

ApPENODlt B



MN van Aarde

116

ApPENDIX B


























MN van Aarde

117

ApPENDIXB















MN van Aarde

118

LIST OF FIGURES






















feeders [36J 80











MN van Aarde

x

OF FIGURES




MN van Aarde

xi

LIST OF TABLES

LIST OF TABLES





M N van Aarde

xii

---------------------------------

CV

NOMENCLATURE

NOMENCLATURE

SCADA

CCTV

CEMA

DEM

kPa

mm

MSHA

ms

mt

MW

NIOSH

OSHA

RampD

tlh

3D




Conveyor


Kilopascal

Millimetres


Metres per second

Metric Tons

Megawatt



Radius of curvature


Tons per hour

Three Dimensional


MN van Aarde

xiii

CHAPTER 1




MN van Aarde

1

CHAPTER 1













significant

o



MN van Aarde

2

CHAPTER 1



























MN van Aarde

3

CHAPTER 1 - ----~--~--------------~--------




Figure 3








MN van Aarde

4

CHAPTER 1











the most extreme




Sishen entails [8]










11 N van Aarde

5

CHAPTER 1

121 Crushing














requirements



MN van Aarde

6

CHAPTER 1
















MN van Aarde

7

CHAPTER 1











conveyor [10]









used








MN van Aarde

8

CHAPTER 1














MN van Aarde

9

CHAPTER 1










MN van Aarde

10

CHAPTER 1








COVERED










MN van Aarde

11

CHAPTER 1






bull Spillage

bull Blocked chutes







transfer chute






MN van Aarde

CHAPTER 1











MN van Aarde

13

CHAPTER 1 --~ ---------------------------shy





dust emissions

















shown in Figure 14


MN van Aarde

14

CHAPTER 1














MN van Aarde

15

CHAPTER 1










MN van Aarde

16

CHAPTER 1













eliminated [13]




MN van Aarde

17

CHAPTER 1



design























MN van Aarde

CHAPTER 1





performance



















new transfer chutes




MN van Aarde

CHAPTER 1







chapter











facility


MN van Aarde

20

CHAPTER 2



MN van Aarde

21

CHAPTER 2

21 PREFACE





















solution





MN van Aarde

22

CHAPTER 2


catered for


the conveyor




the belt










MN van Aarde

23

CHAPTER 2


Aria Unit

Feed Conveyor

Belt Speed r ms

Belt Width mm


Pulley Width mm



Sight Height Data


Drop Height mm


Receiving Conveyor

Belt Speed ms

Belt Width mm

Belt Thickness mm




Material Properties








Inc are [25]


MN van Aarde

24

CHAPTER 2



























MN van Aarde

25

CHAPTER 2














clean [25]










M N van Aarde

26

CHAPTER 2








possible [25]


CONSTRAINTS




handled [1]





I I




L J -





MN van Aarde

27

CHAPTER 2



















MN van Aarde

28

CHAPTER 2















start up



MN van Aarde

29

CHAPTER 2













x

Vo

- ImpactPlate



MN van Aarde

30

CHAPTER 2





















MN van Aarde

31

CHAPTER 2 ---~----------------






reduced [29]


(1)






v = material speed










MN van Aarde

CHAPTER 2

[1 + ( gx )]15 R = vcos8

c (2)

vcos8

Where


v == material speed




















MN van Aarde

33

CHAPTER 2




























MN van Aarde

34

CHAPTER 2


_ IIU _ Im _ I rn _ 171-111 _ u n _ ~ l

_ 4 ~

_ 41 _ 4


~ 1m bull UI2








MN van Aarde

35

CHAPTER 2











is determined and

(4)


MN van Aarde

36

CHAPTER 2

Mass Flow Rate Omh










26 CONCLUSION






MN van Aarde

37

CHAPTER 2










facility limits







MN van Aarde

38

CHAPTER 3


MN van Aarde



39

CHAPTER 3

31 PREFACE




















chute

32 TEST METHODOLOGY






MN van Aarde

40

CHAPTER 3





















sidewalls






MN van Aarde

CHAPTER 3


fUnction







problems





conveyor













MN van Aarde

42

CHAPTER 3









CV4 CV3 CV2 CV1







MN van Aarde

43

CHAPTER 3





90 de-g TRANSFBt











MN van Aarde

44

CHAPTER 3


4 mm and 12 mm



Fine K 5mm

Fine N 8mm

Fine A 8mm

Coarse K 25mm

Coarse D 34mm

Coarse S 12 mm

Coarse A 20mm










MN van Aarde

45

CHAPTER 3












MN van Aarde

46

CHAPTER 3












MN van Aarde

47

CHAPTER 3



























MN van Aarde

48

CHAPTER 3



343 Spillag3















cable


MN van Aarde

49

CHAPTER 3









before loading



MN van Aarde

50

CHAPTER 3

















conveyor system










MN van Aarde

51

CHAPTER 3


constant rate







IlmJ



C)


t) cent


~~ Ii ~ ~ g i i ~ 4 1 J yen i


Time







MN van Aarde

52

CHAPTER 3
















MN van Aarde

53

CHAPTER 3




CV11 CV5 Yes






CV31 CV5 Yes

Yes

Yes





No (Mech trip on




No (Feed to CV 2






MN van Aarde

54

CHAPTER 3





than 10000 tlh






10000 tlh







36 CONCLUSION










MN van Aarde

55

CHAPTER 3




















transfer chutes


MN van Aarde

56

CHAPTER 4


RECURRING PROBLEMS


MN van Aarde

57

CHAPTER 4

41 PREFACE




















feeding conveyor






MN van Aarde

58

CHAPTER 4















t4CLIE SECTION

PURGING POSmON







MN van Aarde

59

CHAPTER 4












I ~

j







MN van Aarde

60

CHAPTER 4
















chute








MN van Aarde

61

CHAPTER 4 -__-----__---_----------shy


















MN van Aarde

62

CHAPTER 4

START-UP CHrrlE

DRlBBIlNG CHUTE
















MN van Aarde

63

CHAPTER 4 -__----- ------shy





















hood surface







MN van Aarde

64

-----

CHAPTER 4


70

--- --~ 6 0

5 0

40 ~_

~ 30 g --- a 20 gt

10

00


















MN van Aarde

65

CHAPTER 4


67

66

65

S 64 amp0 g 6 3

V

v-shy ~ ~

ii ~ gt 62

61 I I 60

o 10 20 30 40 50 60



















MN van Aarde

66

CHAPTER 4


chute














M N van Aarde

67

CHAPTER 4




















e = tan- I ( 1 ) (5)

C Ii







MN van Aarde

CHAPTER 4













MN van Aarde

69

CHAPTER 4

WEAR BOX








inside


MN van Aarde

70

CHAPTER 4 ----_----------------shy




















MN van Aarde

71

CHAPTER 4 ------------_ -- - ---------------shy






section as shown in











MN van Aarde

72

CHAPTER 4
















MN van Aarde

73

CHAPTER 4












MN van Aarde

74

CHAPTER 4










46 CONCLUSION








MN van Aarde

75

CHAPTER 4



















MN van Aarde

76

CHAPTER 5




MN van Aarde

CHAPTER 5

51 PREFACE





















MN van Aarde

78

CHAPTER 5












expensive [34]









chute designs







MN van Aarde

79

CHAPTER 5










collision








time [37]


MN van Aarde

80

CHAPTER 5





equipmentshy




segregation


process


of the simulation














MN van Aarde

81

CHAPTERS













of the design










this dissertation


MN van Aarde

82

CHAPTER 5












MN van Aarde

83

CHAPTER 5




























MN van Aarde

84

CHAPTER 5


software of choice





must be rendered


manufacturing







9 Manufacture

10 Installation











M N van Aarde

85

CHAPTER 5




























MN van Aarde

86

CHAPTER 5




























MN van Aarde

87

CHAPTER 5








APPLICATION





correctly





MN van Aarde

CHAPTER 5


ore type
















MN van Aarde

89

CHAPTER 5


by Figure 52








Off-centre loading

L



MN van Aarde

90

CHAPTER 5


Low velocity layer









transfer point










MN van Aarde

91

CHAPTER 5






HOOD LOCATION









I

L



MN van Aarde

92

CHAPTER 5














MN van Aarde

93

CHAPTER 5


Slower material

L














MN van Aarde

94

CHAPTERS ----------------- -------___ _--shy














chute










MN van Aarde

95

CHAPTER 5

Large radius hood



belt

L


Spoon





MN van Aarde

96

CHAPTERS













however minimised

58 CONCLUSION







with OEM







MN van Aarde

97

CHAPTER 5













MN van Aarde

98

CHAPTER 6



MN van Aarde

99

CHAPTER 6




























MN van Aarde

100

CHAPTER 6





























MN van Aarde

101

CHAPTER 6


























design is reduced


MN van Aarde

102

CHAPTER 6







worn conveyors





















MN van Aarde

103

CHAPTER 6








should be examined












parameters


MN van Aarde

104


REFERENCES











10 Jun 2009











MN van Aarde

105

REFERENCES




4037735





18 Jun 2009



access 22 Jun 2009













MN van Aarde

106

REFERENCES






5 Jul 2009


Power Atticle Oct




Material Handling


26 Apr 2010





1(4) Dec



6(1) Feb



MN van Aarde

107








Bionic research






association 1989




Newcastle Australia





Bionic


MN van Aarde

108

REFERENCES



handling 17 Oct





















MN van Aarde

109

REFERENCES















Handling Industry




MN van Aarde

110

ApPENDIXA



MN van Aarde

11-1

ApPENDIX A



























MN van Aarde

112

ApPENDIX A







Liner T

en aJ c

u

I

i

N en aJ c

u

Cf)

en aJ c

u

I en


(f) shy0

T

aJ ~ j 0 0

N aJ ~ j 0 0 i

I Chrome x x x x x

Carbide


x x x x x x94

Alumina

Ceramic i I

Poly x

Urethane I I I

FLOW TEST WORK










The industry 113

MN van Aarde

ApPENDIXA






WEAR TEST WORK







at the same force









LINER SELECTION





MN van Aarde

ApPEND[xA


ceramics





application


MN van Aarde

115

ApPENODlt B



MN van Aarde

116

ApPENDIX B


























MN van Aarde

117

ApPENDIXB















MN van Aarde

118

OF FIGURES




MN van Aarde

xi

LIST OF TABLES

LIST OF TABLES





M N van Aarde

xii

---------------------------------

CV

NOMENCLATURE

NOMENCLATURE

SCADA

CCTV

CEMA

DEM

kPa

mm

MSHA

ms

mt

MW

NIOSH

OSHA

RampD

tlh

3D




Conveyor


Kilopascal

Millimetres


Metres per second

Metric Tons

Megawatt



Radius of curvature


Tons per hour

Three Dimensional


MN van Aarde

xiii

CHAPTER 1




MN van Aarde

1

CHAPTER 1













significant

o



MN van Aarde

2

CHAPTER 1



























MN van Aarde

3

CHAPTER 1 - ----~--~--------------~--------




Figure 3








MN van Aarde

4

CHAPTER 1











the most extreme




Sishen entails [8]










11 N van Aarde

5

CHAPTER 1

121 Crushing














requirements



MN van Aarde

6

CHAPTER 1
















MN van Aarde

7

CHAPTER 1











conveyor [10]









used








MN van Aarde

8

CHAPTER 1














MN van Aarde

9

CHAPTER 1










MN van Aarde

10

CHAPTER 1








COVERED










MN van Aarde

11

CHAPTER 1






bull Spillage

bull Blocked chutes







transfer chute






MN van Aarde

CHAPTER 1











MN van Aarde

13

CHAPTER 1 --~ ---------------------------shy





dust emissions

















shown in Figure 14


MN van Aarde

14

CHAPTER 1














MN van Aarde

15

CHAPTER 1










MN van Aarde

16

CHAPTER 1













eliminated [13]




MN van Aarde

17

CHAPTER 1



design























MN van Aarde

CHAPTER 1





performance



















new transfer chutes




MN van Aarde

CHAPTER 1







chapter











facility


MN van Aarde

20

CHAPTER 2



MN van Aarde

21

CHAPTER 2

21 PREFACE





















solution





MN van Aarde

22

CHAPTER 2


catered for


the conveyor




the belt










MN van Aarde

23

CHAPTER 2


Aria Unit

Feed Conveyor

Belt Speed r ms

Belt Width mm


Pulley Width mm



Sight Height Data


Drop Height mm


Receiving Conveyor

Belt Speed ms

Belt Width mm

Belt Thickness mm




Material Properties








Inc are [25]


MN van Aarde

24

CHAPTER 2



























MN van Aarde

25

CHAPTER 2














clean [25]










M N van Aarde

26

CHAPTER 2








possible [25]


CONSTRAINTS




handled [1]





I I




L J -





MN van Aarde

27

CHAPTER 2



















MN van Aarde

28

CHAPTER 2















start up



MN van Aarde

29

CHAPTER 2













x

Vo

- ImpactPlate



MN van Aarde

30

CHAPTER 2





















MN van Aarde

31

CHAPTER 2 ---~----------------






reduced [29]


(1)






v = material speed










MN van Aarde

CHAPTER 2

[1 + ( gx )]15 R = vcos8

c (2)

vcos8

Where


v == material speed




















MN van Aarde

33

CHAPTER 2




























MN van Aarde

34

CHAPTER 2


_ IIU _ Im _ I rn _ 171-111 _ u n _ ~ l

_ 4 ~

_ 41 _ 4


~ 1m bull UI2








MN van Aarde

35

CHAPTER 2











is determined and

(4)


MN van Aarde

36

CHAPTER 2

Mass Flow Rate Omh










26 CONCLUSION






MN van Aarde

37

CHAPTER 2










facility limits







MN van Aarde

38

CHAPTER 3


MN van Aarde



39

CHAPTER 3

31 PREFACE




















chute

32 TEST METHODOLOGY






MN van Aarde

40

CHAPTER 3





















sidewalls






MN van Aarde

CHAPTER 3


fUnction







problems





conveyor













MN van Aarde

42

CHAPTER 3









CV4 CV3 CV2 CV1







MN van Aarde

43

CHAPTER 3





90 de-g TRANSFBt











MN van Aarde

44

CHAPTER 3


4 mm and 12 mm



Fine K 5mm

Fine N 8mm

Fine A 8mm

Coarse K 25mm

Coarse D 34mm

Coarse S 12 mm

Coarse A 20mm










MN van Aarde

45

CHAPTER 3












MN van Aarde

46

CHAPTER 3












MN van Aarde

47

CHAPTER 3



























MN van Aarde

48

CHAPTER 3



343 Spillag3















cable


MN van Aarde

49

CHAPTER 3









before loading



MN van Aarde

50

CHAPTER 3

















conveyor system










MN van Aarde

51

CHAPTER 3


constant rate







IlmJ



C)


t) cent


~~ Ii ~ ~ g i i ~ 4 1 J yen i


Time







MN van Aarde

52

CHAPTER 3
















MN van Aarde

53

CHAPTER 3




CV11 CV5 Yes






CV31 CV5 Yes

Yes

Yes





No (Mech trip on




No (Feed to CV 2






MN van Aarde

54

CHAPTER 3





than 10000 tlh






10000 tlh







36 CONCLUSION










MN van Aarde

55

CHAPTER 3




















transfer chutes


MN van Aarde

56

CHAPTER 4


RECURRING PROBLEMS


MN van Aarde

57

CHAPTER 4

41 PREFACE




















feeding conveyor






MN van Aarde

58

CHAPTER 4















t4CLIE SECTION

PURGING POSmON







MN van Aarde

59

CHAPTER 4












I ~

j







MN van Aarde

60

CHAPTER 4
















chute








MN van Aarde

61

CHAPTER 4 -__-----__---_----------shy


















MN van Aarde

62

CHAPTER 4

START-UP CHrrlE

DRlBBIlNG CHUTE
















MN van Aarde

63

CHAPTER 4 -__----- ------shy





















hood surface







MN van Aarde

64

-----

CHAPTER 4


70

--- --~ 6 0

5 0

40 ~_

~ 30 g --- a 20 gt

10

00


















MN van Aarde

65

CHAPTER 4


67

66

65

S 64 amp0 g 6 3

V

v-shy ~ ~

ii ~ gt 62

61 I I 60

o 10 20 30 40 50 60



















MN van Aarde

66

CHAPTER 4


chute














M N van Aarde

67

CHAPTER 4




















e = tan- I ( 1 ) (5)

C Ii







MN van Aarde

CHAPTER 4













MN van Aarde

69

CHAPTER 4

WEAR BOX








inside


MN van Aarde

70

CHAPTER 4 ----_----------------shy




















MN van Aarde

71

CHAPTER 4 ------------_ -- - ---------------shy






section as shown in











MN van Aarde

72

CHAPTER 4
















MN van Aarde

73

CHAPTER 4












MN van Aarde

74

CHAPTER 4










46 CONCLUSION








MN van Aarde

75

CHAPTER 4



















MN van Aarde

76

CHAPTER 5




MN van Aarde

CHAPTER 5

51 PREFACE





















MN van Aarde

78

CHAPTER 5












expensive [34]









chute designs







MN van Aarde

79

CHAPTER 5










collision








time [37]


MN van Aarde

80

CHAPTER 5





equipmentshy




segregation


process


of the simulation














MN van Aarde

81

CHAPTERS













of the design










this dissertation


MN van Aarde

82

CHAPTER 5












MN van Aarde

83

CHAPTER 5




























MN van Aarde

84

CHAPTER 5


software of choice





must be rendered


manufacturing







9 Manufacture

10 Installation











M N van Aarde

85

CHAPTER 5




























MN van Aarde

86

CHAPTER 5




























MN van Aarde

87

CHAPTER 5








APPLICATION





correctly





MN van Aarde

CHAPTER 5


ore type
















MN van Aarde

89

CHAPTER 5


by Figure 52








Off-centre loading

L



MN van Aarde

90

CHAPTER 5


Low velocity layer









transfer point










MN van Aarde

91

CHAPTER 5






HOOD LOCATION









I

L



MN van Aarde

92

CHAPTER 5














MN van Aarde

93

CHAPTER 5


Slower material

L














MN van Aarde

94

CHAPTERS ----------------- -------___ _--shy














chute










MN van Aarde

95

CHAPTER 5

Large radius hood



belt

L


Spoon





MN van Aarde

96

CHAPTERS













however minimised

58 CONCLUSION







with OEM







MN van Aarde

97

CHAPTER 5













MN van Aarde

98

CHAPTER 6



MN van Aarde

99

CHAPTER 6




























MN van Aarde

100

CHAPTER 6





























MN van Aarde

101

CHAPTER 6


























design is reduced


MN van Aarde

102

CHAPTER 6







worn conveyors





















MN van Aarde

103

CHAPTER 6








should be examined












parameters


MN van Aarde

104


REFERENCES











10 Jun 2009











MN van Aarde

105

REFERENCES




4037735





18 Jun 2009



access 22 Jun 2009













MN van Aarde

106

REFERENCES






5 Jul 2009


Power Atticle Oct




Material Handling


26 Apr 2010





1(4) Dec



6(1) Feb



MN van Aarde

107








Bionic research






association 1989




Newcastle Australia





Bionic


MN van Aarde

108

REFERENCES



handling 17 Oct





















MN van Aarde

109

REFERENCES















Handling Industry




MN van Aarde

110

ApPENDIXA



MN van Aarde

11-1

ApPENDIX A



























MN van Aarde

112

ApPENDIX A







Liner T

en aJ c

u

I

i

N en aJ c

u

Cf)

en aJ c

u

I en


(f) shy0

T

aJ ~ j 0 0

N aJ ~ j 0 0 i

I Chrome x x x x x

Carbide


x x x x x x94

Alumina

Ceramic i I

Poly x

Urethane I I I

FLOW TEST WORK










The industry 113

MN van Aarde

ApPENDIXA






WEAR TEST WORK







at the same force









LINER SELECTION





MN van Aarde

ApPEND[xA


ceramics





application


MN van Aarde

115

ApPENODlt B



MN van Aarde

116

ApPENDIX B


























MN van Aarde

117

ApPENDIXB















MN van Aarde

118

LIST OF TABLES

LIST OF TABLES





M N van Aarde

xii

---------------------------------

CV

NOMENCLATURE

NOMENCLATURE

SCADA

CCTV

CEMA

DEM

kPa

mm

MSHA

ms

mt

MW

NIOSH

OSHA

RampD

tlh

3D




Conveyor


Kilopascal

Millimetres


Metres per second

Metric Tons

Megawatt



Radius of curvature


Tons per hour

Three Dimensional


MN van Aarde

xiii

CHAPTER 1




MN van Aarde

1

CHAPTER 1













significant

o



MN van Aarde

2

CHAPTER 1



























MN van Aarde

3

CHAPTER 1 - ----~--~--------------~--------




Figure 3








MN van Aarde

4

CHAPTER 1











the most extreme




Sishen entails [8]










11 N van Aarde

5

CHAPTER 1

121 Crushing














requirements



MN van Aarde

6

CHAPTER 1
















MN van Aarde

7

CHAPTER 1











conveyor [10]









used








MN van Aarde

8

CHAPTER 1














MN van Aarde

9

CHAPTER 1










MN van Aarde

10

CHAPTER 1








COVERED










MN van Aarde

11

CHAPTER 1






bull Spillage

bull Blocked chutes







transfer chute






MN van Aarde

CHAPTER 1











MN van Aarde

13

CHAPTER 1 --~ ---------------------------shy





dust emissions

















shown in Figure 14


MN van Aarde

14

CHAPTER 1














MN van Aarde

15

CHAPTER 1










MN van Aarde

16

CHAPTER 1













eliminated [13]




MN van Aarde

17

CHAPTER 1



design























MN van Aarde

CHAPTER 1





performance



















new transfer chutes




MN van Aarde

CHAPTER 1







chapter











facility


MN van Aarde

20

CHAPTER 2



MN van Aarde

21

CHAPTER 2

21 PREFACE





















solution





MN van Aarde

22

CHAPTER 2


catered for


the conveyor




the belt










MN van Aarde

23

CHAPTER 2


Aria Unit

Feed Conveyor

Belt Speed r ms

Belt Width mm


Pulley Width mm



Sight Height Data


Drop Height mm


Receiving Conveyor

Belt Speed ms

Belt Width mm

Belt Thickness mm




Material Properties








Inc are [25]


MN van Aarde

24

CHAPTER 2



























MN van Aarde

25

CHAPTER 2














clean [25]










M N van Aarde

26

CHAPTER 2








possible [25]


CONSTRAINTS




handled [1]





I I




L J -





MN van Aarde

27

CHAPTER 2



















MN van Aarde

28

CHAPTER 2















start up



MN van Aarde

29

CHAPTER 2













x

Vo

- ImpactPlate



MN van Aarde

30

CHAPTER 2





















MN van Aarde

31

CHAPTER 2 ---~----------------






reduced [29]


(1)






v = material speed










MN van Aarde

CHAPTER 2

[1 + ( gx )]15 R = vcos8

c (2)

vcos8

Where


v == material speed




















MN van Aarde

33

CHAPTER 2




























MN van Aarde

34

CHAPTER 2


_ IIU _ Im _ I rn _ 171-111 _ u n _ ~ l

_ 4 ~

_ 41 _ 4


~ 1m bull UI2








MN van Aarde

35

CHAPTER 2











is determined and

(4)


MN van Aarde

36

CHAPTER 2

Mass Flow Rate Omh










26 CONCLUSION






MN van Aarde

37

CHAPTER 2










facility limits







MN van Aarde

38

CHAPTER 3


MN van Aarde



39

CHAPTER 3

31 PREFACE




















chute

32 TEST METHODOLOGY






MN van Aarde

40

CHAPTER 3





















sidewalls






MN van Aarde

CHAPTER 3


fUnction







problems





conveyor













MN van Aarde

42

CHAPTER 3









CV4 CV3 CV2 CV1







MN van Aarde

43

CHAPTER 3





90 de-g TRANSFBt











MN van Aarde

44

CHAPTER 3


4 mm and 12 mm



Fine K 5mm

Fine N 8mm

Fine A 8mm

Coarse K 25mm

Coarse D 34mm

Coarse S 12 mm

Coarse A 20mm










MN van Aarde

45

CHAPTER 3












MN van Aarde

46

CHAPTER 3












MN van Aarde

47

CHAPTER 3



























MN van Aarde

48

CHAPTER 3



343 Spillag3















cable


MN van Aarde

49

CHAPTER 3









before loading



MN van Aarde

50

CHAPTER 3

















conveyor system










MN van Aarde

51

CHAPTER 3


constant rate







IlmJ



C)


t) cent


~~ Ii ~ ~ g i i ~ 4 1 J yen i


Time







MN van Aarde

52

CHAPTER 3
















MN van Aarde

53

CHAPTER 3




CV11 CV5 Yes






CV31 CV5 Yes

Yes

Yes





No (Mech trip on




No (Feed to CV 2






MN van Aarde

54

CHAPTER 3





than 10000 tlh






10000 tlh







36 CONCLUSION










MN van Aarde

55

CHAPTER 3




















transfer chutes


MN van Aarde

56

CHAPTER 4


RECURRING PROBLEMS


MN van Aarde

57

CHAPTER 4

41 PREFACE




















feeding conveyor






MN van Aarde

58

CHAPTER 4















t4CLIE SECTION

PURGING POSmON







MN van Aarde

59

CHAPTER 4












I ~

j







MN van Aarde

60

CHAPTER 4
















chute








MN van Aarde

61

CHAPTER 4 -__-----__---_----------shy


















MN van Aarde

62

CHAPTER 4

START-UP CHrrlE

DRlBBIlNG CHUTE
















MN van Aarde

63

CHAPTER 4 -__----- ------shy





















hood surface







MN van Aarde

64

-----

CHAPTER 4


70

--- --~ 6 0

5 0

40 ~_

~ 30 g --- a 20 gt

10

00


















MN van Aarde

65

CHAPTER 4


67

66

65

S 64 amp0 g 6 3

V

v-shy ~ ~

ii ~ gt 62

61 I I 60

o 10 20 30 40 50 60



















MN van Aarde

66

CHAPTER 4


chute














M N van Aarde

67

CHAPTER 4




















e = tan- I ( 1 ) (5)

C Ii







MN van Aarde

CHAPTER 4













MN van Aarde

69

CHAPTER 4

WEAR BOX








inside


MN van Aarde

70

CHAPTER 4 ----_----------------shy




















MN van Aarde

71

CHAPTER 4 ------------_ -- - ---------------shy






section as shown in











MN van Aarde

72

CHAPTER 4
















MN van Aarde

73

CHAPTER 4












MN van Aarde

74

CHAPTER 4










46 CONCLUSION








MN van Aarde

75

CHAPTER 4



















MN van Aarde

76

CHAPTER 5




MN van Aarde

CHAPTER 5

51 PREFACE





















MN van Aarde

78

CHAPTER 5












expensive [34]









chute designs







MN van Aarde

79

CHAPTER 5










collision








time [37]


MN van Aarde

80

CHAPTER 5





equipmentshy




segregation


process


of the simulation














MN van Aarde

81

CHAPTERS













of the design










this dissertation


MN van Aarde

82

CHAPTER 5












MN van Aarde

83

CHAPTER 5




























MN van Aarde

84

CHAPTER 5


software of choice





must be rendered


manufacturing







9 Manufacture

10 Installation











M N van Aarde

85

CHAPTER 5




























MN van Aarde

86

CHAPTER 5




























MN van Aarde

87

CHAPTER 5








APPLICATION





correctly





MN van Aarde

CHAPTER 5


ore type
















MN van Aarde

89

CHAPTER 5


by Figure 52








Off-centre loading

L



MN van Aarde

90

CHAPTER 5


Low velocity layer









transfer point










MN van Aarde

91

CHAPTER 5






HOOD LOCATION









I

L



MN van Aarde

92

CHAPTER 5














MN van Aarde

93

CHAPTER 5


Slower material

L














MN van Aarde

94

CHAPTERS ----------------- -------___ _--shy














chute










MN van Aarde

95

CHAPTER 5

Large radius hood



belt

L


Spoon





MN van Aarde

96

CHAPTERS













however minimised

58 CONCLUSION







with OEM







MN van Aarde

97

CHAPTER 5













MN van Aarde

98

CHAPTER 6



MN van Aarde

99

CHAPTER 6




























MN van Aarde

100

CHAPTER 6





























MN van Aarde

101

CHAPTER 6


























design is reduced


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CHAPTER 6







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CHAPTER 6








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parameters


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REFERENCES











10 Jun 2009











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REFERENCES




4037735





18 Jun 2009



access 22 Jun 2009













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REFERENCES






5 Jul 2009


Power Atticle Oct




Material Handling


26 Apr 2010





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Bionic


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REFERENCES



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REFERENCES















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the optimisation of transfer chutes in the bulk materials

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